diff --git a/perl/lib/Nix/Store.xs b/perl/lib/Nix/Store.xs
index 1ca734e75..890310b3e 100644
--- a/perl/lib/Nix/Store.xs
+++ b/perl/lib/Nix/Store.xs
@@ -274,7 +274,8 @@ int checkSignature(SV * publicKey_, SV * sig_, char * msg)
 SV * addToStore(char * srcPath, int recursive, char * algo)
     PPCODE:
         try {
-            auto path = store()->addToStore(std::string(baseNameOf(srcPath)), srcPath, recursive, parseHashType(algo));
+            auto method = recursive ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
+            auto path = store()->addToStore(std::string(baseNameOf(srcPath)), srcPath, method, parseHashType(algo));
             XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(path).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
@@ -285,7 +286,8 @@ SV * makeFixedOutputPath(int recursive, char * algo, char * hash, char * name)
     PPCODE:
         try {
             Hash h(hash, parseHashType(algo));
-            auto path = store()->makeFixedOutputPath(recursive, h, name);
+            auto method = recursive ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
+            auto path = store()->makeFixedOutputPath(method, h, name);
             XPUSHs(sv_2mortal(newSVpv(store()->printStorePath(path).c_str(), 0)));
         } catch (Error & e) {
             croak("%s", e.what());
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index f2c20dd68..82eb1582e 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -1669,7 +1669,7 @@ string EvalState::copyPathToStore(PathSet & context, const Path & path)
     else {
         auto p = settings.readOnlyMode
             ? store->computeStorePathForPath(std::string(baseNameOf(path)), checkSourcePath(path)).first
-            : store->addToStore(std::string(baseNameOf(path)), checkSourcePath(path), true, htSHA256, defaultPathFilter, repair);
+            : store->addToStore(std::string(baseNameOf(path)), checkSourcePath(path), FileIngestionMethod::Recursive, htSHA256, defaultPathFilter, repair);
         dstPath = store->printStorePath(p);
         srcToStore.insert_or_assign(path, std::move(p));
         printMsg(lvlChatty, "copied source '%1%' -> '%2%'", path, dstPath);
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index 0a4236da4..d458ab272 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -562,7 +562,7 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
 
     std::optional<std::string> outputHash;
     std::string outputHashAlgo;
-    bool outputHashRecursive = false;
+    auto ingestionMethod = FileIngestionMethod::Flat;
 
     StringSet outputs;
     outputs.insert("out");
@@ -573,8 +573,8 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
         vomit("processing attribute '%1%'", key);
 
         auto handleHashMode = [&](const std::string & s) {
-            if (s == "recursive") outputHashRecursive = true;
-            else if (s == "flat") outputHashRecursive = false;
+            if (s == "recursive") ingestionMethod = FileIngestionMethod::Recursive;
+            else if (s == "flat") ingestionMethod = FileIngestionMethod::Flat;
             else throw EvalError("invalid value '%s' for 'outputHashMode' attribute, at %s", s, posDrvName);
         };
 
@@ -721,11 +721,14 @@ static void prim_derivationStrict(EvalState & state, const Pos & pos, Value * *
         HashType ht = outputHashAlgo.empty() ? htUnknown : parseHashType(outputHashAlgo);
         Hash h(*outputHash, ht);
 
-        auto outPath = state.store->makeFixedOutputPath(outputHashRecursive, h, drvName);
+        auto outPath = state.store->makeFixedOutputPath(ingestionMethod, h, drvName);
         if (!jsonObject) drv.env["out"] = state.store->printStorePath(outPath);
-        drv.outputs.insert_or_assign("out", DerivationOutput(std::move(outPath),
-                (outputHashRecursive ? "r:" : "") + printHashType(h.type),
-                h.to_string(Base16, false)));
+        drv.outputs.insert_or_assign("out", DerivationOutput {
+            std::move(outPath),
+            (ingestionMethod == FileIngestionMethod::Recursive ? "r:" : "")
+                + printHashType(h.type),
+            h.to_string(Base16, false),
+        });
     }
 
     else {
@@ -1039,7 +1042,7 @@ static void prim_toFile(EvalState & state, const Pos & pos, Value * * args, Valu
 
 
 static void addPath(EvalState & state, const Pos & pos, const string & name, const Path & path_,
-    Value * filterFun, bool recursive, const Hash & expectedHash, Value & v)
+    Value * filterFun, FileIngestionMethod method, const Hash & expectedHash, Value & v)
 {
     const auto path = evalSettings.pureEval && expectedHash ?
         path_ :
@@ -1070,12 +1073,12 @@ static void addPath(EvalState & state, const Pos & pos, const string & name, con
 
     std::optional<StorePath> expectedStorePath;
     if (expectedHash)
-        expectedStorePath = state.store->makeFixedOutputPath(recursive, expectedHash, name);
+        expectedStorePath = state.store->makeFixedOutputPath(method, expectedHash, name);
     Path dstPath;
     if (!expectedHash || !state.store->isValidPath(*expectedStorePath)) {
         dstPath = state.store->printStorePath(settings.readOnlyMode
-            ? state.store->computeStorePathForPath(name, path, recursive, htSHA256, filter).first
-            : state.store->addToStore(name, path, recursive, htSHA256, filter, state.repair));
+            ? state.store->computeStorePathForPath(name, path, method, htSHA256, filter).first
+            : state.store->addToStore(name, path, method, htSHA256, filter, state.repair));
         if (expectedHash && expectedStorePath != state.store->parseStorePath(dstPath))
             throw Error("store path mismatch in (possibly filtered) path added from '%s'", path);
     } else
@@ -1096,7 +1099,7 @@ static void prim_filterSource(EvalState & state, const Pos & pos, Value * * args
     if (args[0]->type != tLambda)
         throw TypeError(format("first argument in call to 'filterSource' is not a function but %1%, at %2%") % showType(*args[0]) % pos);
 
-    addPath(state, pos, std::string(baseNameOf(path)), path, args[0], true, Hash(), v);
+    addPath(state, pos, std::string(baseNameOf(path)), path, args[0], FileIngestionMethod::Recursive, Hash(), v);
 }
 
 static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value & v)
@@ -1105,7 +1108,7 @@ static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value
     Path path;
     string name;
     Value * filterFun = nullptr;
-    auto recursive = true;
+    auto method = FileIngestionMethod::Recursive;
     Hash expectedHash;
 
     for (auto & attr : *args[0]->attrs) {
@@ -1121,7 +1124,7 @@ static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value
             state.forceValue(*attr.value, pos);
             filterFun = attr.value;
         } else if (n == "recursive")
-            recursive = state.forceBool(*attr.value, *attr.pos);
+            method = FileIngestionMethod { state.forceBool(*attr.value, *attr.pos) };
         else if (n == "sha256")
             expectedHash = Hash(state.forceStringNoCtx(*attr.value, *attr.pos), htSHA256);
         else
@@ -1132,7 +1135,7 @@ static void prim_path(EvalState & state, const Pos & pos, Value * * args, Value
     if (name.empty())
         name = baseNameOf(path);
 
-    addPath(state, pos, name, path, filterFun, recursive, expectedHash, v);
+    addPath(state, pos, name, path, filterFun, method, expectedHash, v);
 }
 
 
diff --git a/src/libfetchers/git.cc b/src/libfetchers/git.cc
index 7c18cf67f..17cc60228 100644
--- a/src/libfetchers/git.cc
+++ b/src/libfetchers/git.cc
@@ -195,7 +195,7 @@ struct GitInput : Input
                     return files.count(file);
                 };
 
-                auto storePath = store->addToStore("source", actualUrl, true, htSHA256, filter);
+                auto storePath = store->addToStore("source", actualUrl, FileIngestionMethod::Recursive, htSHA256, filter);
 
                 auto tree = Tree {
                     .actualPath = store->printStorePath(storePath),
@@ -347,7 +347,7 @@ struct GitInput : Input
             unpackTarfile(*source, tmpDir);
         }
 
-        auto storePath = store->addToStore(name, tmpDir, true, htSHA256, filter);
+        auto storePath = store->addToStore(name, tmpDir, FileIngestionMethod::Recursive, htSHA256, filter);
 
         auto lastModified = std::stoull(runProgram("git", true, { "-C", repoDir, "log", "-1", "--format=%ct", input->rev->gitRev() }));
 
diff --git a/src/libfetchers/mercurial.cc b/src/libfetchers/mercurial.cc
index 1d6571571..2e0d4bf4d 100644
--- a/src/libfetchers/mercurial.cc
+++ b/src/libfetchers/mercurial.cc
@@ -114,7 +114,7 @@ struct MercurialInput : Input
                     return files.count(file);
                 };
 
-                auto storePath = store->addToStore("source", actualUrl, true, htSHA256, filter);
+                auto storePath = store->addToStore("source", actualUrl, FileIngestionMethod::Recursive, htSHA256, filter);
 
                 return {Tree {
                     .actualPath = store->printStorePath(storePath),
diff --git a/src/libfetchers/tarball.cc b/src/libfetchers/tarball.cc
index 695525b31..bf2b2a5ff 100644
--- a/src/libfetchers/tarball.cc
+++ b/src/libfetchers/tarball.cc
@@ -67,10 +67,10 @@ DownloadFileResult downloadFile(
         StringSink sink;
         dumpString(*res.data, sink);
         auto hash = hashString(htSHA256, *res.data);
-        ValidPathInfo info(store->makeFixedOutputPath(false, hash, name));
+        ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Flat, hash, name));
         info.narHash = hashString(htSHA256, *sink.s);
         info.narSize = sink.s->size();
-        info.ca = makeFixedOutputCA(false, hash);
+        info.ca = makeFixedOutputCA(FileIngestionMethod::Flat, hash);
         store->addToStore(info, sink.s, NoRepair, NoCheckSigs);
         storePath = std::move(info.path);
     }
@@ -141,7 +141,7 @@ Tree downloadTarball(
             throw nix::Error("tarball '%s' contains an unexpected number of top-level files", url);
         auto topDir = tmpDir + "/" + members.begin()->name;
         lastModified = lstat(topDir).st_mtime;
-        unpackedStorePath = store->addToStore(name, topDir, true, htSHA256, defaultPathFilter, NoRepair);
+        unpackedStorePath = store->addToStore(name, topDir, FileIngestionMethod::Recursive, htSHA256, defaultPathFilter, NoRepair);
     }
 
     Attrs infoAttrs({
diff --git a/src/libfetchers/tree-info.cc b/src/libfetchers/tree-info.cc
index 5788e94a1..b2d8cfc8d 100644
--- a/src/libfetchers/tree-info.cc
+++ b/src/libfetchers/tree-info.cc
@@ -8,7 +8,7 @@ namespace nix::fetchers {
 StorePath TreeInfo::computeStorePath(Store & store) const
 {
     assert(narHash);
-    return store.makeFixedOutputPath(true, narHash, "source");
+    return store.makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, "source");
 }
 
 }
diff --git a/src/libstore/binary-cache-store.cc b/src/libstore/binary-cache-store.cc
index 3a2d84861..f13736c58 100644
--- a/src/libstore/binary-cache-store.cc
+++ b/src/libstore/binary-cache-store.cc
@@ -327,7 +327,7 @@ void BinaryCacheStore::queryPathInfoUncached(const StorePath & storePath,
 }
 
 StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath,
-    bool recursive, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
+    FileIngestionMethod method, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
 {
     // FIXME: some cut&paste from LocalStore::addToStore().
 
@@ -336,7 +336,7 @@ StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath
        small files. */
     StringSink sink;
     Hash h;
-    if (recursive) {
+    if (method == FileIngestionMethod::Recursive) {
         dumpPath(srcPath, sink, filter);
         h = hashString(hashAlgo, *sink.s);
     } else {
@@ -345,7 +345,7 @@ StorePath BinaryCacheStore::addToStore(const string & name, const Path & srcPath
         h = hashString(hashAlgo, s);
     }
 
-    ValidPathInfo info(makeFixedOutputPath(recursive, h, name));
+    ValidPathInfo info(makeFixedOutputPath(method, h, name));
 
     addToStore(info, sink.s, repair, CheckSigs, nullptr);
 
diff --git a/src/libstore/binary-cache-store.hh b/src/libstore/binary-cache-store.hh
index aa13c1cb4..4ff5609ed 100644
--- a/src/libstore/binary-cache-store.hh
+++ b/src/libstore/binary-cache-store.hh
@@ -79,7 +79,7 @@ public:
         std::shared_ptr<FSAccessor> accessor) override;
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive, HashType hashAlgo,
+        FileIngestionMethod method, HashType hashAlgo,
         PathFilter & filter, RepairFlag repair) override;
 
     StorePath addTextToStore(const string & name, const string & s,
diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index a2b16f95c..f5c132a83 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -2734,7 +2734,7 @@ struct RestrictedStore : public LocalFSStore
     { throw Error("queryPathFromHashPart"); }
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive = true, HashType hashAlgo = htSHA256,
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256,
         PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) override
     { throw Error("addToStore"); }
 
@@ -2747,9 +2747,9 @@ struct RestrictedStore : public LocalFSStore
     }
 
     StorePath addToStoreFromDump(const string & dump, const string & name,
-        bool recursive = true, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair) override
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair) override
     {
-        auto path = next->addToStoreFromDump(dump, name, recursive, hashAlgo, repair);
+        auto path = next->addToStoreFromDump(dump, name, method, hashAlgo, repair);
         goal.addDependency(path);
         return path;
     }
@@ -3692,10 +3692,10 @@ void DerivationGoal::registerOutputs()
 
         if (fixedOutput) {
 
-            bool recursive; Hash h;
-            i.second.parseHashInfo(recursive, h);
+            FileIngestionMethod outputHashMode; Hash h;
+            i.second.parseHashInfo(outputHashMode, h);
 
-            if (!recursive) {
+            if (outputHashMode == FileIngestionMethod::Flat) {
                 /* The output path should be a regular file without execute permission. */
                 if (!S_ISREG(st.st_mode) || (st.st_mode & S_IXUSR) != 0)
                     throw BuildError(
@@ -3705,9 +3705,11 @@ void DerivationGoal::registerOutputs()
 
             /* Check the hash. In hash mode, move the path produced by
                the derivation to its content-addressed location. */
-            Hash h2 = recursive ? hashPath(h.type, actualPath).first : hashFile(h.type, actualPath);
+            Hash h2 = outputHashMode == FileIngestionMethod::Recursive
+                ? hashPath(h.type, actualPath).first
+                : hashFile(h.type, actualPath);
 
-            auto dest = worker.store.makeFixedOutputPath(recursive, h2, i.second.path.name());
+            auto dest = worker.store.makeFixedOutputPath(outputHashMode, h2, i.second.path.name());
 
             if (h != h2) {
 
@@ -3736,7 +3738,7 @@ void DerivationGoal::registerOutputs()
             else
                 assert(worker.store.parseStorePath(path) == dest);
 
-            ca = makeFixedOutputCA(recursive, h2);
+            ca = makeFixedOutputCA(outputHashMode, h2);
         }
 
         /* Get rid of all weird permissions.  This also checks that
@@ -3957,7 +3959,9 @@ void DerivationGoal::checkOutputs(const std::map<Path, ValidPathInfo> & outputs)
 
                 auto spec = parseReferenceSpecifiers(worker.store, *drv, *value);
 
-                auto used = recursive ? cloneStorePathSet(getClosure(info.path).first) : cloneStorePathSet(info.references);
+                auto used = recursive
+                    ? cloneStorePathSet(getClosure(info.path).first)
+                    : cloneStorePathSet(info.references);
 
                 if (recursive && checks.ignoreSelfRefs)
                     used.erase(info.path);
diff --git a/src/libstore/daemon.cc b/src/libstore/daemon.cc
index 8e9f9d71b..f1afdff69 100644
--- a/src/libstore/daemon.cc
+++ b/src/libstore/daemon.cc
@@ -355,20 +355,24 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
     }
 
     case wopAddToStore: {
-        bool fixed, recursive;
         std::string s, baseName;
-        from >> baseName >> fixed /* obsolete */ >> recursive >> s;
-        /* Compatibility hack. */
-        if (!fixed) {
-            s = "sha256";
-            recursive = true;
+        FileIngestionMethod method;
+        {
+            bool fixed, recursive;
+            from >> baseName >> fixed /* obsolete */ >> recursive >> s;
+            method = FileIngestionMethod { recursive };
+            /* Compatibility hack. */
+            if (!fixed) {
+                s = "sha256";
+                method = FileIngestionMethod::Recursive;
+            }
         }
         HashType hashAlgo = parseHashType(s);
 
         TeeSource savedNAR(from);
         RetrieveRegularNARSink savedRegular;
 
-        if (recursive) {
+        if (method == FileIngestionMethod::Recursive) {
             /* Get the entire NAR dump from the client and save it to
                a string so that we can pass it to
                addToStoreFromDump(). */
@@ -380,7 +384,11 @@ static void performOp(TunnelLogger * logger, ref<Store> store,
         logger->startWork();
         if (!savedRegular.regular) throw Error("regular file expected");
 
-        auto path = store->addToStoreFromDump(recursive ? *savedNAR.data : savedRegular.s, baseName, recursive, hashAlgo);
+        auto path = store->addToStoreFromDump(
+            method == FileIngestionMethod::Recursive ? *savedNAR.data : savedRegular.s,
+            baseName,
+            method,
+            hashAlgo);
         logger->stopWork();
 
         to << store->printStorePath(path);
diff --git a/src/libstore/derivations.cc b/src/libstore/derivations.cc
index 0067032af..c68e7b16b 100644
--- a/src/libstore/derivations.cc
+++ b/src/libstore/derivations.cc
@@ -9,13 +9,13 @@
 namespace nix {
 
 
-void DerivationOutput::parseHashInfo(bool & recursive, Hash & hash) const
+void DerivationOutput::parseHashInfo(FileIngestionMethod & recursive, Hash & hash) const
 {
-    recursive = false;
+    recursive = FileIngestionMethod::Flat;
     string algo = hashAlgo;
 
     if (string(algo, 0, 2) == "r:") {
-        recursive = true;
+        recursive = FileIngestionMethod::Recursive;
         algo = string(algo, 2);
     }
 
diff --git a/src/libstore/derivations.hh b/src/libstore/derivations.hh
index 7222d25e5..b1224b93b 100644
--- a/src/libstore/derivations.hh
+++ b/src/libstore/derivations.hh
@@ -22,7 +22,7 @@ struct DerivationOutput
         , hashAlgo(std::move(hashAlgo))
         , hash(std::move(hash))
     { }
-    void parseHashInfo(bool & recursive, Hash & hash) const;
+    void parseHashInfo(FileIngestionMethod & recursive, Hash & hash) const;
 };
 
 typedef std::map<string, DerivationOutput> DerivationOutputs;
diff --git a/src/libstore/legacy-ssh-store.cc b/src/libstore/legacy-ssh-store.cc
index 458266be0..af20d389b 100644
--- a/src/libstore/legacy-ssh-store.cc
+++ b/src/libstore/legacy-ssh-store.cc
@@ -195,7 +195,7 @@ struct LegacySSHStore : public Store
     { unsupported("queryPathFromHashPart"); }
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive, HashType hashAlgo,
+        FileIngestionMethod method, HashType hashAlgo,
         PathFilter & filter, RepairFlag repair) override
     { unsupported("addToStore"); }
 
diff --git a/src/libstore/local-store.cc b/src/libstore/local-store.cc
index ae7513ad8..80851b591 100644
--- a/src/libstore/local-store.cc
+++ b/src/libstore/local-store.cc
@@ -557,10 +557,10 @@ void LocalStore::checkDerivationOutputs(const StorePath & drvPath, const Derivat
         if (out == drv.outputs.end())
             throw Error("derivation '%s' does not have an output named 'out'", printStorePath(drvPath));
 
-        bool recursive; Hash h;
-        out->second.parseHashInfo(recursive, h);
+        FileIngestionMethod method; Hash h;
+        out->second.parseHashInfo(method, h);
 
-        check(makeFixedOutputPath(recursive, h, drvName), out->second.path, "out");
+        check(makeFixedOutputPath(method, h, drvName), out->second.path, "out");
     }
 
     else {
@@ -1043,11 +1043,11 @@ void LocalStore::addToStore(const ValidPathInfo & info, Source & source,
 
 
 StorePath LocalStore::addToStoreFromDump(const string & dump, const string & name,
-    bool recursive, HashType hashAlgo, RepairFlag repair)
+    FileIngestionMethod method, HashType hashAlgo, RepairFlag repair)
 {
     Hash h = hashString(hashAlgo, dump);
 
-    auto dstPath = makeFixedOutputPath(recursive, h, name);
+    auto dstPath = makeFixedOutputPath(method, h, name);
 
     addTempRoot(dstPath);
 
@@ -1067,7 +1067,7 @@ StorePath LocalStore::addToStoreFromDump(const string & dump, const string & nam
 
             autoGC();
 
-            if (recursive) {
+            if (method == FileIngestionMethod::Recursive) {
                 StringSource source(dump);
                 restorePath(realPath, source);
             } else
@@ -1080,7 +1080,7 @@ StorePath LocalStore::addToStoreFromDump(const string & dump, const string & nam
                above (if called with recursive == true and hashAlgo ==
                sha256); otherwise, compute it here. */
             HashResult hash;
-            if (recursive) {
+            if (method == FileIngestionMethod::Recursive) {
                 hash.first = hashAlgo == htSHA256 ? h : hashString(htSHA256, dump);
                 hash.second = dump.size();
             } else
@@ -1091,7 +1091,7 @@ StorePath LocalStore::addToStoreFromDump(const string & dump, const string & nam
             ValidPathInfo info(dstPath.clone());
             info.narHash = hash.first;
             info.narSize = hash.second;
-            info.ca = makeFixedOutputCA(recursive, h);
+            info.ca = makeFixedOutputCA(method, h);
             registerValidPath(info);
         }
 
@@ -1103,7 +1103,7 @@ StorePath LocalStore::addToStoreFromDump(const string & dump, const string & nam
 
 
 StorePath LocalStore::addToStore(const string & name, const Path & _srcPath,
-    bool recursive, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
+    FileIngestionMethod method, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
 {
     Path srcPath(absPath(_srcPath));
 
@@ -1111,12 +1111,12 @@ StorePath LocalStore::addToStore(const string & name, const Path & _srcPath,
        method for very large paths, but `copyPath' is mainly used for
        small files. */
     StringSink sink;
-    if (recursive)
+    if (method == FileIngestionMethod::Recursive)
         dumpPath(srcPath, sink, filter);
     else
         sink.s = make_ref<std::string>(readFile(srcPath));
 
-    return addToStoreFromDump(*sink.s, name, recursive, hashAlgo, repair);
+    return addToStoreFromDump(*sink.s, name, method, hashAlgo, repair);
 }
 
 
diff --git a/src/libstore/local-store.hh b/src/libstore/local-store.hh
index 16aeab0ad..c1e75390c 100644
--- a/src/libstore/local-store.hh
+++ b/src/libstore/local-store.hh
@@ -149,7 +149,7 @@ public:
         std::shared_ptr<FSAccessor> accessor) override;
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive, HashType hashAlgo,
+        FileIngestionMethod method, HashType hashAlgo,
         PathFilter & filter, RepairFlag repair) override;
 
     /* Like addToStore(), but the contents of the path are contained
@@ -157,7 +157,7 @@ public:
        true) or simply the contents of a regular file (if recursive ==
        false). */
     StorePath addToStoreFromDump(const string & dump, const string & name,
-        bool recursive = true, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair) override;
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair) override;
 
     StorePath addTextToStore(const string & name, const string & s,
         const StorePathSet & references, RepairFlag repair) override;
diff --git a/src/libstore/path.hh b/src/libstore/path.hh
index c90bb1fff..5122e7422 100644
--- a/src/libstore/path.hh
+++ b/src/libstore/path.hh
@@ -73,6 +73,11 @@ const size_t storePathHashLen = 32; // i.e. 160 bits
 /* Extension of derivations in the Nix store. */
 const std::string drvExtension = ".drv";
 
+enum struct FileIngestionMethod : uint8_t {
+    Flat = false,
+    Recursive = true
+};
+
 struct StorePathWithOutputs
 {
     StorePath path;
diff --git a/src/libstore/remote-store.cc b/src/libstore/remote-store.cc
index 8c55da268..5c36693e6 100644
--- a/src/libstore/remote-store.cc
+++ b/src/libstore/remote-store.cc
@@ -484,7 +484,7 @@ void RemoteStore::addToStore(const ValidPathInfo & info, Source & source,
 
 
 StorePath RemoteStore::addToStore(const string & name, const Path & _srcPath,
-    bool recursive, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
+    FileIngestionMethod method, HashType hashAlgo, PathFilter & filter, RepairFlag repair)
 {
     if (repair) throw Error("repairing is not supported when building through the Nix daemon");
 
@@ -492,10 +492,12 @@ StorePath RemoteStore::addToStore(const string & name, const Path & _srcPath,
 
     Path srcPath(absPath(_srcPath));
 
-    conn->to << wopAddToStore << name
-       << ((hashAlgo == htSHA256 && recursive) ? 0 : 1) /* backwards compatibility hack */
-       << (recursive ? 1 : 0)
-       << printHashType(hashAlgo);
+    conn->to
+        << wopAddToStore
+        << name
+        << ((hashAlgo == htSHA256 && method == FileIngestionMethod::Recursive) ? 0 : 1) /* backwards compatibility hack */
+        << (method == FileIngestionMethod::Recursive ? 1 : 0)
+        << printHashType(hashAlgo);
 
     try {
         conn->to.written = 0;
diff --git a/src/libstore/remote-store.hh b/src/libstore/remote-store.hh
index f301a97d8..3c86b4524 100644
--- a/src/libstore/remote-store.hh
+++ b/src/libstore/remote-store.hh
@@ -65,7 +65,7 @@ public:
         std::shared_ptr<FSAccessor> accessor) override;
 
     StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive = true, HashType hashAlgo = htSHA256,
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256,
         PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) override;
 
     StorePath addTextToStore(const string & name, const string & s,
diff --git a/src/libstore/store-api.cc b/src/libstore/store-api.cc
index e5282bb30..d479b86cb 100644
--- a/src/libstore/store-api.cc
+++ b/src/libstore/store-api.cc
@@ -172,19 +172,22 @@ static std::string makeType(
 
 
 StorePath Store::makeFixedOutputPath(
-    bool recursive,
+    FileIngestionMethod recursive,
     const Hash & hash,
     std::string_view name,
     const StorePathSet & references,
     bool hasSelfReference) const
 {
-    if (hash.type == htSHA256 && recursive) {
+    if (hash.type == htSHA256 && recursive == FileIngestionMethod::Recursive) {
         return makeStorePath(makeType(*this, "source", references, hasSelfReference), hash, name);
     } else {
         assert(references.empty());
-        return makeStorePath("output:out", hashString(htSHA256,
-                "fixed:out:" + (recursive ? (string) "r:" : "") +
-                hash.to_string(Base16) + ":"), name);
+        return makeStorePath("output:out",
+            hashString(htSHA256,
+                "fixed:out:"
+                + (recursive == FileIngestionMethod::Recursive ? (string) "r:" : "")
+                + hash.to_string(Base16) + ":"),
+            name);
     }
 }
 
@@ -201,10 +204,12 @@ StorePath Store::makeTextPath(std::string_view name, const Hash & hash,
 
 
 std::pair<StorePath, Hash> Store::computeStorePathForPath(std::string_view name,
-    const Path & srcPath, bool recursive, HashType hashAlgo, PathFilter & filter) const
+    const Path & srcPath, FileIngestionMethod method, HashType hashAlgo, PathFilter & filter) const
 {
-    Hash h = recursive ? hashPath(hashAlgo, srcPath, filter).first : hashFile(hashAlgo, srcPath);
-    return std::make_pair(makeFixedOutputPath(recursive, h, name), h);
+    Hash h = method == FileIngestionMethod::Recursive
+        ? hashPath(hashAlgo, srcPath, filter).first
+        : hashFile(hashAlgo, srcPath);
+    return std::make_pair(makeFixedOutputPath(method, h, name), h);
 }
 
 
@@ -782,8 +787,8 @@ bool ValidPathInfo::isContentAddressed(const Store & store) const
     }
 
     else if (hasPrefix(ca, "fixed:")) {
-        bool recursive = ca.compare(6, 2, "r:") == 0;
-        Hash hash(std::string(ca, recursive ? 8 : 6));
+        FileIngestionMethod recursive { ca.compare(6, 2, "r:") == 0 };
+        Hash hash(std::string(ca, recursive == FileIngestionMethod::Recursive ? 8 : 6));
         auto refs = cloneStorePathSet(references);
         bool hasSelfReference = false;
         if (refs.count(path)) {
@@ -827,9 +832,11 @@ Strings ValidPathInfo::shortRefs() const
 }
 
 
-std::string makeFixedOutputCA(bool recursive, const Hash & hash)
+std::string makeFixedOutputCA(FileIngestionMethod recursive, const Hash & hash)
 {
-    return "fixed:" + (recursive ? (std::string) "r:" : "") + hash.to_string();
+    return "fixed:"
+        + (recursive == FileIngestionMethod::Recursive ? (std::string) "r:" : "")
+        + hash.to_string();
 }
 
 
diff --git a/src/libstore/store-api.hh b/src/libstore/store-api.hh
index 81014763d..3def209a6 100644
--- a/src/libstore/store-api.hh
+++ b/src/libstore/store-api.hh
@@ -44,7 +44,6 @@ enum CheckSigsFlag : bool { NoCheckSigs = false, CheckSigs = true };
 enum SubstituteFlag : bool { NoSubstitute = false, Substitute = true };
 enum AllowInvalidFlag : bool { DisallowInvalid = false, AllowInvalid = true };
 
-
 /* Magic header of exportPath() output (obsolete). */
 const uint32_t exportMagic = 0x4558494e;
 
@@ -347,7 +346,7 @@ public:
     StorePath makeOutputPath(const string & id,
         const Hash & hash, std::string_view name) const;
 
-    StorePath makeFixedOutputPath(bool recursive,
+    StorePath makeFixedOutputPath(FileIngestionMethod method,
         const Hash & hash, std::string_view name,
         const StorePathSet & references = {},
         bool hasSelfReference = false) const;
@@ -359,7 +358,7 @@ public:
        store path to which srcPath is to be copied.  Returns the store
        path and the cryptographic hash of the contents of srcPath. */
     std::pair<StorePath, Hash> computeStorePathForPath(std::string_view name,
-        const Path & srcPath, bool recursive = true,
+        const Path & srcPath, FileIngestionMethod method = FileIngestionMethod::Recursive,
         HashType hashAlgo = htSHA256, PathFilter & filter = defaultPathFilter) const;
 
     /* Preparatory part of addTextToStore().
@@ -463,12 +462,12 @@ public:
        The function object `filter' can be used to exclude files (see
        libutil/archive.hh). */
     virtual StorePath addToStore(const string & name, const Path & srcPath,
-        bool recursive = true, HashType hashAlgo = htSHA256,
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256,
         PathFilter & filter = defaultPathFilter, RepairFlag repair = NoRepair) = 0;
 
     // FIXME: remove?
     virtual StorePath addToStoreFromDump(const string & dump, const string & name,
-        bool recursive = true, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair)
+        FileIngestionMethod method = FileIngestionMethod::Recursive, HashType hashAlgo = htSHA256, RepairFlag repair = NoRepair)
     {
         throw Error("addToStoreFromDump() is not supported by this store");
     }
@@ -851,7 +850,7 @@ std::optional<ValidPathInfo> decodeValidPathInfo(
 
 /* Compute the content-addressability assertion (ValidPathInfo::ca)
    for paths created by makeFixedOutputPath() / addToStore(). */
-std::string makeFixedOutputCA(bool recursive, const Hash & hash);
+std::string makeFixedOutputCA(FileIngestionMethod method, const Hash & hash);
 
 
 /* Split URI into protocol+hierarchy part and its parameter set. */
diff --git a/src/nix-prefetch-url/nix-prefetch-url.cc b/src/nix-prefetch-url/nix-prefetch-url.cc
index 748554b9c..5a686c8cd 100644
--- a/src/nix-prefetch-url/nix-prefetch-url.cc
+++ b/src/nix-prefetch-url/nix-prefetch-url.cc
@@ -159,7 +159,8 @@ static int _main(int argc, char * * argv)
         std::optional<StorePath> storePath;
         if (args.size() == 2) {
             expectedHash = Hash(args[1], ht);
-            storePath = store->makeFixedOutputPath(unpack, expectedHash, name);
+            const auto recursive = unpack ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
+            storePath = store->makeFixedOutputPath(recursive, expectedHash, name);
             if (store->isValidPath(*storePath))
                 hash = expectedHash;
             else
@@ -208,13 +209,15 @@ static int _main(int argc, char * * argv)
             if (expectedHash != Hash(ht) && expectedHash != hash)
                 throw Error(format("hash mismatch for '%1%'") % uri);
 
+            const auto recursive = unpack ? FileIngestionMethod::Recursive : FileIngestionMethod::Flat;
+
             /* Copy the file to the Nix store. FIXME: if RemoteStore
                implemented addToStoreFromDump() and downloadFile()
                supported a sink, we could stream the download directly
                into the Nix store. */
-            storePath = store->addToStore(name, tmpFile, unpack, ht);
+            storePath = store->addToStore(name, tmpFile, recursive, ht);
 
-            assert(*storePath == store->makeFixedOutputPath(unpack, hash, name));
+            assert(*storePath == store->makeFixedOutputPath(recursive, hash, name));
         }
 
         stopProgressBar();
diff --git a/src/nix-store/nix-store.cc b/src/nix-store/nix-store.cc
index fcc00175a..3a3060ad8 100644
--- a/src/nix-store/nix-store.cc
+++ b/src/nix-store/nix-store.cc
@@ -174,10 +174,10 @@ static void opAdd(Strings opFlags, Strings opArgs)
    store. */
 static void opAddFixed(Strings opFlags, Strings opArgs)
 {
-    bool recursive = false;
+    auto recursive = FileIngestionMethod::Flat;
 
     for (auto & i : opFlags)
-        if (i == "--recursive") recursive = true;
+        if (i == "--recursive") recursive = FileIngestionMethod::Recursive;
         else throw UsageError(format("unknown flag '%1%'") % i);
 
     if (opArgs.empty())
@@ -194,10 +194,10 @@ static void opAddFixed(Strings opFlags, Strings opArgs)
 /* Hack to support caching in `nix-prefetch-url'. */
 static void opPrintFixedPath(Strings opFlags, Strings opArgs)
 {
-    bool recursive = false;
+    auto recursive = FileIngestionMethod::Flat;
 
     for (auto i : opFlags)
-        if (i == "--recursive") recursive = true;
+        if (i == "--recursive") recursive = FileIngestionMethod::Recursive;
         else throw UsageError(format("unknown flag '%1%'") % i);
 
     if (opArgs.size() != 3)
diff --git a/src/nix/add-to-store.cc b/src/nix/add-to-store.cc
index 1d298903b..4b4ba81cb 100644
--- a/src/nix/add-to-store.cc
+++ b/src/nix/add-to-store.cc
@@ -45,10 +45,10 @@ struct CmdAddToStore : MixDryRun, StoreCommand
 
         auto narHash = hashString(htSHA256, *sink.s);
 
-        ValidPathInfo info(store->makeFixedOutputPath(true, narHash, *namePart));
+        ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, *namePart));
         info.narHash = narHash;
         info.narSize = sink.s->size();
-        info.ca = makeFixedOutputCA(true, info.narHash);
+        info.ca = makeFixedOutputCA(FileIngestionMethod::Recursive, info.narHash);
 
         if (!dryRun)
             store->addToStore(info, sink.s);
diff --git a/src/nix/hash.cc b/src/nix/hash.cc
index 366314227..0a7c343d0 100644
--- a/src/nix/hash.cc
+++ b/src/nix/hash.cc
@@ -9,15 +9,14 @@ using namespace nix;
 
 struct CmdHash : Command
 {
-    enum Mode { mFile, mPath };
-    Mode mode;
+    FileIngestionMethod mode;
     Base base = SRI;
     bool truncate = false;
     HashType ht = htSHA256;
     std::vector<std::string> paths;
     std::optional<std::string> modulus;
 
-    CmdHash(Mode mode) : mode(mode)
+    CmdHash(FileIngestionMethod mode) : mode(mode)
     {
         mkFlag(0, "sri", "print hash in SRI format", &base, SRI);
         mkFlag(0, "base64", "print hash in base-64", &base, Base64);
@@ -36,9 +35,14 @@ struct CmdHash : Command
 
     std::string description() override
     {
-        return mode == mFile
-            ? "print cryptographic hash of a regular file"
-            : "print cryptographic hash of the NAR serialisation of a path";
+        const char* d;
+        switch (mode) {
+        case FileIngestionMethod::Flat:
+            d = "print cryptographic hash of a regular file";
+        case FileIngestionMethod::Recursive:
+            d = "print cryptographic hash of the NAR serialisation of a path";
+        };
+        return d;
     }
 
     Category category() override { return catUtility; }
@@ -53,10 +57,14 @@ struct CmdHash : Command
             else
                 hashSink = std::make_unique<HashSink>(ht);
 
-            if (mode == mFile)
+            switch (mode) {
+            case FileIngestionMethod::Flat:
                 readFile(path, *hashSink);
-            else
+                break;
+            case FileIngestionMethod::Recursive:
                 dumpPath(path, *hashSink);
+                break;
+            }
 
             Hash h = hashSink->finish().first;
             if (truncate && h.hashSize > 20) h = compressHash(h, 20);
@@ -65,8 +73,8 @@ struct CmdHash : Command
     }
 };
 
-static RegisterCommand r1("hash-file", [](){ return make_ref<CmdHash>(CmdHash::mFile); });
-static RegisterCommand r2("hash-path", [](){ return make_ref<CmdHash>(CmdHash::mPath); });
+static RegisterCommand r1("hash-file", [](){ return make_ref<CmdHash>(FileIngestionMethod::Flat); });
+static RegisterCommand r2("hash-path", [](){ return make_ref<CmdHash>(FileIngestionMethod::Recursive); });
 
 struct CmdToBase : Command
 {
@@ -137,7 +145,7 @@ static int compatNixHash(int argc, char * * argv)
     });
 
     if (op == opHash) {
-        CmdHash cmd(flat ? CmdHash::mFile : CmdHash::mPath);
+        CmdHash cmd(flat ? FileIngestionMethod::Flat : FileIngestionMethod::Recursive);
         cmd.ht = ht;
         cmd.base = base32 ? Base32 : Base16;
         cmd.truncate = truncate;
diff --git a/src/nix/make-content-addressable.cc b/src/nix/make-content-addressable.cc
index 8803461f4..3e7ff544d 100644
--- a/src/nix/make-content-addressable.cc
+++ b/src/nix/make-content-addressable.cc
@@ -77,12 +77,12 @@ struct CmdMakeContentAddressable : StorePathsCommand, MixJSON
 
             auto narHash = hashModuloSink.finish().first;
 
-            ValidPathInfo info(store->makeFixedOutputPath(true, narHash, path.name(), references, hasSelfReference));
+            ValidPathInfo info(store->makeFixedOutputPath(FileIngestionMethod::Recursive, narHash, path.name(), references, hasSelfReference));
             info.references = std::move(references);
             if (hasSelfReference) info.references.insert(info.path.clone());
             info.narHash = narHash;
             info.narSize = sink.s->size();
-            info.ca = makeFixedOutputCA(true, info.narHash);
+            info.ca = makeFixedOutputCA(FileIngestionMethod::Recursive, info.narHash);
 
             if (!json)
                 printError("rewrote '%s' to '%s'", pathS, store->printStorePath(info.path));