diff --git a/src/libexpr/common-eval-args.cc b/src/libexpr/common-eval-args.cc
index ecae2ca1f..fffca4ac5 100644
--- a/src/libexpr/common-eval-args.cc
+++ b/src/libexpr/common-eval-args.cc
@@ -79,7 +79,7 @@ Bindings * MixEvalArgs::getAutoArgs(EvalState & state)
         if (i.second[0] == 'E')
             state.mkThunk_(*v, state.parseExprFromString(string(i.second, 1), absPath(".")));
         else
-            mkString(*v, string(i.second, 1));
+            v->mkString(((std::string_view) i.second).substr(1));
         res.insert(state.symbols.create(i.first), v);
     }
     return res.finish();
diff --git a/src/libexpr/eval.cc b/src/libexpr/eval.cc
index 0710ce270..2ac872745 100644
--- a/src/libexpr/eval.cc
+++ b/src/libexpr/eval.cc
@@ -766,25 +766,12 @@ LocalNoInline(void addErrorTrace(Error & e, const Pos & pos, const char * s, con
 }
 
 
-void mkString(Value & v, const char * s)
-{
-    v.mkString(dupString(s));
-}
-
-
 void Value::mkString(std::string_view s)
 {
     mkString(dupStringWithLen(s.data(), s.size()));
 }
 
 
-Value & mkString(Value & v, std::string_view s, const PathSet & context)
-{
-    v.mkString(s, context);
-    return v;
-}
-
-
 void Value::mkString(std::string_view s, const PathSet & context)
 {
     mkString(s);
diff --git a/src/libexpr/eval.hh b/src/libexpr/eval.hh
index 44ccc6593..c7f74d7b7 100644
--- a/src/libexpr/eval.hh
+++ b/src/libexpr/eval.hh
@@ -44,8 +44,6 @@ struct Env
 };
 
 
-Value & mkString(Value & v, std::string_view s, const PathSet & context = PathSet());
-
 void copyContext(const Value & v, PathSet & context);
 
 
diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
index c549c5971..15e8d4b06 100644
--- a/src/libexpr/flake/flake.cc
+++ b/src/libexpr/flake/flake.cc
@@ -682,7 +682,7 @@ void callFlake(EvalState & state,
     auto vTmp1 = state.allocValue();
     auto vTmp2 = state.allocValue();
 
-    mkString(*vLocks, lockedFlake.lockFile.to_string());
+    vLocks->mkString(lockedFlake.lockFile.to_string());
 
     emitTreeAttrs(
         state,
@@ -692,7 +692,7 @@ void callFlake(EvalState & state,
         false,
         lockedFlake.flake.forceDirty);
 
-    mkString(*vRootSubdir, lockedFlake.flake.lockedRef.subdir);
+    vRootSubdir->mkString(lockedFlake.flake.lockedRef.subdir);
 
     if (!state.vCallFlake) {
         state.vCallFlake = allocRootValue(state.allocValue());
diff --git a/src/libexpr/json-to-value.cc b/src/libexpr/json-to-value.cc
index 9ca5ac86d..3825ca9a9 100644
--- a/src/libexpr/json-to-value.cc
+++ b/src/libexpr/json-to-value.cc
@@ -113,8 +113,11 @@ public:
 
     bool string(string_t & val)
     {
-        return handle_value<void(Value&, const char*)>(mkString, val.c_str());
+        rs->value(state).mkString(val);
+        rs->add();
+        return true;
     }
+
 #if NLOHMANN_JSON_VERSION_MAJOR >= 3 && NLOHMANN_JSON_VERSION_MINOR >= 8
     bool binary(binary_t&)
     {
diff --git a/src/libexpr/primops.cc b/src/libexpr/primops.cc
index daf5fc927..cb18fe494 100644
--- a/src/libexpr/primops.cc
+++ b/src/libexpr/primops.cc
@@ -1285,7 +1285,7 @@ static RegisterPrimOp primop_derivationStrict(RegisterPrimOp::Info {
    ‘out’. */
 static void prim_placeholder(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
-    mkString(v, hashPlaceholder(state.forceStringNoCtx(*args[0], pos)));
+    v.mkString(hashPlaceholder(state.forceStringNoCtx(*args[0], pos)));
 }
 
 static RegisterPrimOp primop_placeholder({
@@ -1310,7 +1310,7 @@ static void prim_toPath(EvalState & state, const Pos & pos, Value * * args, Valu
 {
     PathSet context;
     Path path = state.coerceToPath(pos, *args[0], context);
-    mkString(v, canonPath(path), context);
+    v.mkString(canonPath(path), context);
 }
 
 static RegisterPrimOp primop_toPath({
@@ -1354,7 +1354,7 @@ static void prim_storePath(EvalState & state, const Pos & pos, Value * * args, V
     if (!settings.readOnlyMode)
         state.store->ensurePath(path2);
     context.insert(state.store->printStorePath(path2));
-    mkString(v, path, context);
+    v.mkString(path, context);
 }
 
 static RegisterPrimOp primop_storePath({
@@ -1420,7 +1420,7 @@ static RegisterPrimOp primop_pathExists({
 static void prim_baseNameOf(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
     PathSet context;
-    mkString(v, baseNameOf(state.coerceToString(pos, *args[0], context, false, false)), context);
+    v.mkString(baseNameOf(state.coerceToString(pos, *args[0], context, false, false)), context);
 }
 
 static RegisterPrimOp primop_baseNameOf({
@@ -1441,7 +1441,7 @@ static void prim_dirOf(EvalState & state, const Pos & pos, Value * * args, Value
 {
     PathSet context;
     Path dir = dirOf(state.coerceToString(pos, *args[0], context, false, false));
-    if (args[0]->type() == nPath) mkPath(v, dir.c_str()); else mkString(v, dir, context);
+    if (args[0]->type() == nPath) mkPath(v, dir.c_str()); else v.mkString(dir, context);
 }
 
 static RegisterPrimOp primop_dirOf({
@@ -1470,7 +1470,7 @@ static void prim_readFile(EvalState & state, const Pos & pos, Value * * args, Va
     string s = readFile(path);
     if (s.find((char) 0) != string::npos)
         throw Error("the contents of the file '%1%' cannot be represented as a Nix string", path);
-    mkString(v, s.c_str());
+    v.mkString(s);
 }
 
 static RegisterPrimOp primop_readFile({
@@ -1549,7 +1549,7 @@ static void prim_hashFile(EvalState & state, const Pos & pos, Value * * args, Va
         throw EvalError("cannot read '%s' since path '%s' is not valid, at %s", path, e.path, pos);
     }
 
-    mkString(v, hashFile(*ht, path).to_string(Base16, false));
+    v.mkString(hashFile(*ht, path).to_string(Base16, false));
 }
 
 static RegisterPrimOp primop_hashFile({
@@ -1626,7 +1626,7 @@ static void prim_toXML(EvalState & state, const Pos & pos, Value * * args, Value
     std::ostringstream out;
     PathSet context;
     printValueAsXML(state, true, false, *args[0], out, context, pos);
-    mkString(v, out.str(), context);
+    v.mkString(out.str(), context);
 }
 
 static RegisterPrimOp primop_toXML({
@@ -1734,7 +1734,7 @@ static void prim_toJSON(EvalState & state, const Pos & pos, Value * * args, Valu
     std::ostringstream out;
     PathSet context;
     printValueAsJSON(state, true, *args[0], pos, out, context);
-    mkString(v, out.str(), context);
+    v.mkString(out.str(), context);
 }
 
 static RegisterPrimOp primop_toJSON({
@@ -1808,7 +1808,7 @@ static void prim_toFile(EvalState & state, const Pos & pos, Value * * args, Valu
        result, since `storePath' itself has references to the paths
        used in args[1]. */
 
-    mkString(v, storePath, {storePath});
+    v.mkString(storePath, {storePath});
 }
 
 static RegisterPrimOp primop_toFile({
@@ -1925,10 +1925,10 @@ static void addPath(
             /* Call the filter function.  The first argument is the path,
                the second is a string indicating the type of the file. */
             Value arg1;
-            mkString(arg1, path);
+            arg1.mkString(path);
 
             Value arg2;
-            mkString(arg2,
+            arg2.mkString(
                 S_ISREG(st.st_mode) ? "regular" :
                 S_ISDIR(st.st_mode) ? "directory" :
                 S_ISLNK(st.st_mode) ? "symlink" :
@@ -1955,7 +1955,7 @@ static void addPath(
         } else
             dstPath = state.store->printStorePath(*expectedStorePath);
 
-        mkString(v, dstPath, {dstPath});
+        v.mkString(dstPath, {dstPath});
 
         state.allowPath(dstPath);
 
@@ -3303,7 +3303,7 @@ static void prim_toString(EvalState & state, const Pos & pos, Value * * args, Va
 {
     PathSet context;
     string s = state.coerceToString(pos, *args[0], context, true, false);
-    mkString(v, s, context);
+    v.mkString(s, context);
 }
 
 static RegisterPrimOp primop_toString({
@@ -3347,7 +3347,7 @@ static void prim_substring(EvalState & state, const Pos & pos, Value * * args, V
             .errPos = pos
         });
 
-    mkString(v, (unsigned int) start >= s.size() ? "" : string(s, start, len), context);
+    v.mkString((unsigned int) start >= s.size() ? "" : string(s, start, len), context);
 }
 
 static RegisterPrimOp primop_substring({
@@ -3401,7 +3401,7 @@ static void prim_hashString(EvalState & state, const Pos & pos, Value * * args,
     PathSet context; // discarded
     string s = state.forceString(*args[1], context, pos);
 
-    mkString(v, hashString(*ht, s).to_string(Base16, false));
+    v.mkString(hashString(*ht, s).to_string(Base16, false));
 }
 
 static RegisterPrimOp primop_hashString({
@@ -3451,7 +3451,7 @@ void prim_match(EvalState & state, const Pos & pos, Value * * args, Value & v)
             if (!match[i+1].matched)
                 mkNull(*(v.listElems()[i] = state.allocValue()));
             else
-                mkString(*(v.listElems()[i] = state.allocValue()), match[i + 1].str().c_str());
+                (v.listElems()[i] = state.allocValue())->mkString(match[i + 1].str());
         }
 
     } catch (std::regex_error &e) {
@@ -3526,7 +3526,6 @@ static void prim_split(EvalState & state, const Pos & pos, Value * * args, Value
         const size_t len = std::distance(begin, end);
         state.mkList(v, 2 * len + 1);
         size_t idx = 0;
-        Value * elem;
 
         if (len == 0) {
             v.listElems()[idx++] = args[1];
@@ -3538,12 +3537,11 @@ static void prim_split(EvalState & state, const Pos & pos, Value * * args, Value
             std::smatch match = *i;
 
             // Add a string for non-matched characters.
-            elem = v.listElems()[idx++] = state.allocValue();
-            mkString(*elem, match.prefix().str().c_str());
+            (v.listElems()[idx++] = state.allocValue())->mkString(match.prefix().str());
 
             // Add a list for matched substrings.
             const size_t slen = match.size() - 1;
-            elem = v.listElems()[idx++] = state.allocValue();
+            auto elem = v.listElems()[idx++] = state.allocValue();
 
             // Start at 1, beacause the first match is the whole string.
             state.mkList(*elem, slen);
@@ -3551,15 +3549,14 @@ static void prim_split(EvalState & state, const Pos & pos, Value * * args, Value
                 if (!match[si + 1].matched)
                     mkNull(*(elem->listElems()[si] = state.allocValue()));
                 else
-                    mkString(*(elem->listElems()[si] = state.allocValue()), match[si + 1].str().c_str());
+                    (elem->listElems()[si] = state.allocValue())->mkString(match[si + 1].str());
             }
 
             // Add a string for non-matched suffix characters.
-            if (idx == 2 * len) {
-                elem = v.listElems()[idx++] = state.allocValue();
-                mkString(*elem, match.suffix().str().c_str());
-            }
+            if (idx == 2 * len)
+                (v.listElems()[idx++] = state.allocValue())->mkString(match.suffix().str());
         }
+
         assert(idx == 2 * len + 1);
 
     } catch (std::regex_error &e) {
@@ -3631,7 +3628,7 @@ static void prim_concatStringsSep(EvalState & state, const Pos & pos, Value * *
         res += state.coerceToString(pos, *elem, context);
     }
 
-    mkString(v, res, context);
+    v.mkString(res, context);
 }
 
 static RegisterPrimOp primop_concatStringsSep({
@@ -3700,7 +3697,7 @@ static void prim_replaceStrings(EvalState & state, const Pos & pos, Value * * ar
         }
     }
 
-    mkString(v, res, context);
+    v.mkString(res, context);
 }
 
 static RegisterPrimOp primop_replaceStrings({
@@ -3781,11 +3778,8 @@ static void prim_splitVersion(EvalState & state, const Pos & pos, Value * * args
         components.emplace_back(std::move(component));
     }
     state.mkList(v, components.size());
-    unsigned int n = 0;
-    for (auto & component : components) {
-        auto listElem = v.listElems()[n++] = state.allocValue();
-        mkString(*listElem, std::move(component));
-    }
+    for (const auto & [n, component] : enumerate(components))
+        (v.listElems()[n] = state.allocValue())->mkString(std::move(component));
 }
 
 static RegisterPrimOp primop_splitVersion({
@@ -3851,14 +3845,14 @@ void EvalState::createBaseEnv()
         mkInt(v, time(0));
         addConstant("__currentTime", v);
 
-        mkString(v, settings.thisSystem.get());
+        v.mkString(settings.thisSystem.get());
         addConstant("__currentSystem", v);
     }
 
-    mkString(v, nixVersion);
+    v.mkString(nixVersion);
     addConstant("__nixVersion", v);
 
-    mkString(v, store->storeDir);
+    v.mkString(store->storeDir);
     addConstant("__storeDir", v);
 
     /* Language version.  This should be increased every time a new
diff --git a/src/libexpr/primops/context.cc b/src/libexpr/primops/context.cc
index ab08303d8..321c3c301 100644
--- a/src/libexpr/primops/context.cc
+++ b/src/libexpr/primops/context.cc
@@ -7,8 +7,7 @@ namespace nix {
 static void prim_unsafeDiscardStringContext(EvalState & state, const Pos & pos, Value * * args, Value & v)
 {
     PathSet context;
-    string s = state.coerceToString(pos, *args[0], context);
-    mkString(v, s, PathSet());
+    v.mkString(state.coerceToString(pos, *args[0], context));
 }
 
 static RegisterPrimOp primop_unsafeDiscardStringContext("__unsafeDiscardStringContext", 1, prim_unsafeDiscardStringContext);
@@ -39,7 +38,7 @@ static void prim_unsafeDiscardOutputDependency(EvalState & state, const Pos & po
     for (auto & p : context)
         context2.insert(p.at(0) == '=' ? string(p, 1) : p);
 
-    mkString(v, s, context2);
+    v.mkString(s, context2);
 }
 
 static RegisterPrimOp primop_unsafeDiscardOutputDependency("__unsafeDiscardOutputDependency", 1, prim_unsafeDiscardOutputDependency);
@@ -186,7 +185,7 @@ static void prim_appendContext(EvalState & state, const Pos & pos, Value * * arg
         }
     }
 
-    mkString(v, orig, context);
+    v.mkString(orig, context);
 }
 
 static RegisterPrimOp primop_appendContext("__appendContext", 2, prim_appendContext);
diff --git a/src/libexpr/primops/fetchTree.cc b/src/libexpr/primops/fetchTree.cc
index a97bfcae7..6647bd35c 100644
--- a/src/libexpr/primops/fetchTree.cc
+++ b/src/libexpr/primops/fetchTree.cc
@@ -247,7 +247,7 @@ static void fetch(EvalState & state, const Pos & pos, Value * * args, Value & v,
     state.allowPath(storePath);
 
     auto path = state.store->printStorePath(storePath);
-    mkString(v, path, PathSet({path}));
+    v.mkString(path, PathSet({path}));
 }
 
 static void prim_fetchurl(EvalState & state, const Pos & pos, Value * * args, Value & v)
diff --git a/src/libexpr/primops/fromTOML.cc b/src/libexpr/primops/fromTOML.cc
index a328b6736..bae0189ab 100644
--- a/src/libexpr/primops/fromTOML.cc
+++ b/src/libexpr/primops/fromTOML.cc
@@ -52,7 +52,7 @@ static void prim_fromTOML(EvalState & state, const Pos & pos, Value * * args, Va
                 mkFloat(v, toml::get<NixFloat>(t));
                 break;;
             case toml::value_t::string:
-                mkString(v, toml::get<std::string>(t));
+                v.mkString(toml::get<std::string>(t));
                 break;;
             case toml::value_t::local_datetime:
             case toml::value_t::offset_datetime:
diff --git a/src/libexpr/value.hh b/src/libexpr/value.hh
index a8fea02dc..94a17136f 100644
--- a/src/libexpr/value.hh
+++ b/src/libexpr/value.hh
@@ -424,9 +424,6 @@ static inline void mkString(Value & v, const Symbol & s)
 }
 
 
-void mkString(Value & v, const char * s);
-
-
 void mkPath(Value & v, const char * s);
 
 
diff --git a/src/nix-env/nix-env.cc b/src/nix-env/nix-env.cc
index 171f1c440..7393d91f9 100644
--- a/src/nix-env/nix-env.cc
+++ b/src/nix-env/nix-env.cc
@@ -678,8 +678,8 @@ static void opUpgrade(Globals & globals, Strings opFlags, Strings opArgs)
 static void setMetaFlag(EvalState & state, DrvInfo & drv,
     const string & name, const string & value)
 {
-    Value * v = state.allocValue();
-    mkString(*v, value.c_str());
+    auto v = state.allocValue();
+    v->mkString(value);
     drv.setMeta(name, v);
 }