diff --git a/src/libcmd/installables.cc b/src/libcmd/installables.cc
index ce40986d0..b80ae4df1 100644
--- a/src/libcmd/installables.cc
+++ b/src/libcmd/installables.cc
@@ -446,19 +446,19 @@ struct InstallableAttrPath : InstallableValue
     SourceExprCommand & cmd;
     RootValue v;
     std::string attrPath;
-    OutputsSpec outputsSpec;
+    ExtendedOutputsSpec extendedOutputsSpec;
 
     InstallableAttrPath(
         ref<EvalState> state,
         SourceExprCommand & cmd,
         Value * v,
         const std::string & attrPath,
-        OutputsSpec outputsSpec)
+        ExtendedOutputsSpec extendedOutputsSpec)
         : InstallableValue(state)
         , cmd(cmd)
         , v(allocRootValue(v))
         , attrPath(attrPath)
-        , outputsSpec(std::move(outputsSpec))
+        , extendedOutputsSpec(std::move(extendedOutputsSpec))
     { }
 
     std::string what() const override { return attrPath; }
@@ -490,10 +490,10 @@ struct InstallableAttrPath : InstallableValue
 
             std::set<std::string> outputsToInstall;
 
-            if (auto outputNames = std::get_if<OutputNames>(&outputsSpec))
+            if (auto outputNames = std::get_if<OutputNames>(&extendedOutputsSpec))
                 outputsToInstall = *outputNames;
             else
-                for (auto & output : drvInfo.queryOutputs(false, std::get_if<DefaultOutputs>(&outputsSpec)))
+                for (auto & output : drvInfo.queryOutputs(false, std::get_if<DefaultOutputs>(&extendedOutputsSpec)))
                     outputsToInstall.insert(output.first);
 
             auto derivedPath = byDrvPath.emplace(*drvPath, DerivedPath::Built { .drvPath = *drvPath }).first;
@@ -581,7 +581,7 @@ InstallableFlake::InstallableFlake(
     ref<EvalState> state,
     FlakeRef && flakeRef,
     std::string_view fragment,
-    OutputsSpec outputsSpec,
+    ExtendedOutputsSpec extendedOutputsSpec,
     Strings attrPaths,
     Strings prefixes,
     const flake::LockFlags & lockFlags)
@@ -589,7 +589,7 @@ InstallableFlake::InstallableFlake(
       flakeRef(flakeRef),
       attrPaths(fragment == "" ? attrPaths : Strings{(std::string) fragment}),
       prefixes(fragment == "" ? Strings{} : prefixes),
-      outputsSpec(std::move(outputsSpec)),
+      extendedOutputsSpec(std::move(extendedOutputsSpec)),
       lockFlags(lockFlags)
 {
     if (cmd && cmd->getAutoArgs(*state)->size())
@@ -657,7 +657,7 @@ DerivedPathsWithInfo InstallableFlake::toDerivedPaths()
             priority = aPriority->getInt();
     }
 
-    if (outputsToInstall.empty() || std::get_if<AllOutputs>(&outputsSpec)) {
+    if (outputsToInstall.empty() || std::get_if<AllOutputs>(&extendedOutputsSpec)) {
         outputsToInstall.clear();
         if (auto aOutputs = attr->maybeGetAttr(state->sOutputs))
             for (auto & s : aOutputs->getListOfStrings())
@@ -667,7 +667,7 @@ DerivedPathsWithInfo InstallableFlake::toDerivedPaths()
     if (outputsToInstall.empty())
         outputsToInstall.insert("out");
 
-    if (auto outputNames = std::get_if<OutputNames>(&outputsSpec))
+    if (auto outputNames = std::get_if<OutputNames>(&extendedOutputsSpec))
         outputsToInstall = *outputNames;
 
     return {{
@@ -680,7 +680,7 @@ DerivedPathsWithInfo InstallableFlake::toDerivedPaths()
             .originalRef = flakeRef,
             .resolvedRef = getLockedFlake()->flake.lockedRef,
             .attrPath = attrPath,
-            .outputsSpec = outputsSpec,
+            .extendedOutputsSpec = extendedOutputsSpec,
         }
     }};
 }
@@ -797,12 +797,12 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
         }
 
         for (auto & s : ss) {
-            auto [prefix, outputsSpec] = OutputsSpec::parse(s);
+            auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse(s);
             result.push_back(
                 std::make_shared<InstallableAttrPath>(
                     state, *this, vFile,
                     prefix == "." ? "" : prefix,
-                    outputsSpec));
+                    extendedOutputsSpec));
         }
 
     } else {
@@ -837,13 +837,13 @@ std::vector<std::shared_ptr<Installable>> SourceExprCommand::parseInstallables(
             }
 
             try {
-                auto [flakeRef, fragment, outputsSpec] = parseFlakeRefWithFragmentAndOutputsSpec(s, absPath("."));
+                auto [flakeRef, fragment, extendedOutputsSpec] = parseFlakeRefWithFragmentAndExtendedOutputsSpec(s, absPath("."));
                 result.push_back(std::make_shared<InstallableFlake>(
                         this,
                         getEvalState(),
                         std::move(flakeRef),
                         fragment,
-                        outputsSpec,
+                        extendedOutputsSpec,
                         getDefaultFlakeAttrPaths(),
                         getDefaultFlakeAttrPathPrefixes(),
                         lockFlags));
diff --git a/src/libcmd/installables.hh b/src/libcmd/installables.hh
index 9b92cc4be..3d12639b0 100644
--- a/src/libcmd/installables.hh
+++ b/src/libcmd/installables.hh
@@ -59,7 +59,7 @@ struct ExtraPathInfo
     std::optional<FlakeRef> resolvedRef;
     std::optional<std::string> attrPath;
     // FIXME: merge with DerivedPath's 'outputs' field?
-    std::optional<OutputsSpec> outputsSpec;
+    std::optional<ExtendedOutputsSpec> extendedOutputsSpec;
 };
 
 /* A derived path with any additional info that commands might
@@ -169,7 +169,7 @@ struct InstallableFlake : InstallableValue
     FlakeRef flakeRef;
     Strings attrPaths;
     Strings prefixes;
-    OutputsSpec outputsSpec;
+    ExtendedOutputsSpec extendedOutputsSpec;
     const flake::LockFlags & lockFlags;
     mutable std::shared_ptr<flake::LockedFlake> _lockedFlake;
 
@@ -178,7 +178,7 @@ struct InstallableFlake : InstallableValue
         ref<EvalState> state,
         FlakeRef && flakeRef,
         std::string_view fragment,
-        OutputsSpec outputsSpec,
+        ExtendedOutputsSpec extendedOutputsSpec,
         Strings attrPaths,
         Strings prefixes,
         const flake::LockFlags & lockFlags);
diff --git a/src/libexpr/flake/flakeref.cc b/src/libexpr/flake/flakeref.cc
index cfa279fb4..bc61e2c9a 100644
--- a/src/libexpr/flake/flakeref.cc
+++ b/src/libexpr/flake/flakeref.cc
@@ -238,15 +238,15 @@ std::pair<fetchers::Tree, FlakeRef> FlakeRef::fetchTree(ref<Store> store) const
     return {std::move(tree), FlakeRef(std::move(lockedInput), subdir)};
 }
 
-std::tuple<FlakeRef, std::string, OutputsSpec> parseFlakeRefWithFragmentAndOutputsSpec(
+std::tuple<FlakeRef, std::string, ExtendedOutputsSpec> parseFlakeRefWithFragmentAndExtendedOutputsSpec(
     const std::string & url,
     const std::optional<Path> & baseDir,
     bool allowMissing,
     bool isFlake)
 {
-    auto [prefix, outputsSpec] = OutputsSpec::parse(url);
+    auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse(url);
     auto [flakeRef, fragment] = parseFlakeRefWithFragment(prefix, baseDir, allowMissing, isFlake);
-    return {std::move(flakeRef), fragment, outputsSpec};
+    return {std::move(flakeRef), fragment, extendedOutputsSpec};
 }
 
 }
diff --git a/src/libexpr/flake/flakeref.hh b/src/libexpr/flake/flakeref.hh
index 4ec79fb73..c4142fc20 100644
--- a/src/libexpr/flake/flakeref.hh
+++ b/src/libexpr/flake/flakeref.hh
@@ -80,7 +80,7 @@ std::pair<FlakeRef, std::string> parseFlakeRefWithFragment(
 std::optional<std::pair<FlakeRef, std::string>> maybeParseFlakeRefWithFragment(
     const std::string & url, const std::optional<Path> & baseDir = {});
 
-std::tuple<FlakeRef, std::string, OutputsSpec> parseFlakeRefWithFragmentAndOutputsSpec(
+std::tuple<FlakeRef, std::string, ExtendedOutputsSpec> parseFlakeRefWithFragmentAndExtendedOutputsSpec(
     const std::string & url,
     const std::optional<Path> & baseDir = {},
     bool allowMissing = false,
diff --git a/src/libstore/outputs-spec.cc b/src/libstore/outputs-spec.cc
index b5ea7e325..c446976bc 100644
--- a/src/libstore/outputs-spec.cc
+++ b/src/libstore/outputs-spec.cc
@@ -6,7 +6,7 @@
 
 namespace nix {
 
-std::pair<std::string, OutputsSpec> OutputsSpec::parse(std::string s)
+std::pair<std::string, ExtendedOutputsSpec> ExtendedOutputsSpec::parse(std::string s)
 {
     static std::regex regex(R"((.*)\^((\*)|([a-z]+(,[a-z]+)*)))");
 
@@ -20,43 +20,43 @@ std::pair<std::string, OutputsSpec> OutputsSpec::parse(std::string s)
     return {match[1], tokenizeString<OutputNames>(match[4].str(), ",")};
 }
 
-std::string OutputsSpec::to_string() const
+std::string ExtendedOutputsSpec::to_string() const
 {
     return std::visit(overloaded {
-        [&](const OutputsSpec::Default &) -> std::string {
+        [&](const ExtendedOutputsSpec::Default &) -> std::string {
             return "";
         },
-        [&](const OutputsSpec::All &) -> std::string {
+        [&](const ExtendedOutputsSpec::All &) -> std::string {
             return "*";
         },
-        [&](const OutputsSpec::Names & outputNames) -> std::string {
+        [&](const ExtendedOutputsSpec::Names & outputNames) -> std::string {
             return "^" + concatStringsSep(",", outputNames);
         },
     }, raw());
 }
 
-void to_json(nlohmann::json & json, const OutputsSpec & outputsSpec)
+void to_json(nlohmann::json & json, const ExtendedOutputsSpec & extendedOutputsSpec)
 {
-    if (std::get_if<DefaultOutputs>(&outputsSpec))
+    if (std::get_if<DefaultOutputs>(&extendedOutputsSpec))
         json = nullptr;
 
-    else if (std::get_if<AllOutputs>(&outputsSpec))
+    else if (std::get_if<AllOutputs>(&extendedOutputsSpec))
         json = std::vector<std::string>({"*"});
 
-    else if (auto outputNames = std::get_if<OutputNames>(&outputsSpec))
+    else if (auto outputNames = std::get_if<OutputNames>(&extendedOutputsSpec))
         json = *outputNames;
 }
 
-void from_json(const nlohmann::json & json, OutputsSpec & outputsSpec)
+void from_json(const nlohmann::json & json, ExtendedOutputsSpec & extendedOutputsSpec)
 {
     if (json.is_null())
-        outputsSpec = DefaultOutputs();
+        extendedOutputsSpec = DefaultOutputs();
     else {
         auto names = json.get<OutputNames>();
         if (names == OutputNames({"*"}))
-            outputsSpec = AllOutputs();
+            extendedOutputsSpec = AllOutputs();
         else
-            outputsSpec = names;
+            extendedOutputsSpec = names;
     }
 }
 
diff --git a/src/libstore/outputs-spec.hh b/src/libstore/outputs-spec.hh
index 6f886ccb6..5ed711a62 100644
--- a/src/libstore/outputs-spec.hh
+++ b/src/libstore/outputs-spec.hh
@@ -17,10 +17,10 @@ struct DefaultOutputs {
     bool operator < (const DefaultOutputs & _) const { return false; }
 };
 
-typedef std::variant<DefaultOutputs, AllOutputs, OutputNames> _OutputsSpecRaw;
+typedef std::variant<DefaultOutputs, AllOutputs, OutputNames> _ExtendedOutputsSpecRaw;
 
-struct OutputsSpec : _OutputsSpecRaw {
-    using Raw = _OutputsSpecRaw;
+struct ExtendedOutputsSpec : _ExtendedOutputsSpecRaw {
+    using Raw = _ExtendedOutputsSpecRaw;
     using Raw::Raw;
 
     using Names = OutputNames;
@@ -33,12 +33,12 @@ struct OutputsSpec : _OutputsSpecRaw {
 
     /* Parse a string of the form 'prefix^output1,...outputN' or
        'prefix^*', returning the prefix and the outputs spec. */
-    static std::pair<std::string, OutputsSpec> parse(std::string s);
+    static std::pair<std::string, ExtendedOutputsSpec> parse(std::string s);
 
     std::string to_string() const;
 };
 
-void to_json(nlohmann::json &, const OutputsSpec &);
-void from_json(const nlohmann::json &, OutputsSpec &);
+void to_json(nlohmann::json &, const ExtendedOutputsSpec &);
+void from_json(const nlohmann::json &, ExtendedOutputsSpec &);
 
 }
diff --git a/src/libstore/tests/outputs-spec.cc b/src/libstore/tests/outputs-spec.cc
index 552380837..a3dd42341 100644
--- a/src/libstore/tests/outputs-spec.cc
+++ b/src/libstore/tests/outputs-spec.cc
@@ -4,42 +4,42 @@
 
 namespace nix {
 
-TEST(OutputsSpec_parse, basic)
+TEST(ExtendedOutputsSpec_parse, basic)
 {
     {
-        auto [prefix, outputsSpec] = OutputsSpec::parse("foo");
+        auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse("foo");
         ASSERT_EQ(prefix, "foo");
-        ASSERT_TRUE(std::get_if<DefaultOutputs>(&outputsSpec));
+        ASSERT_TRUE(std::get_if<DefaultOutputs>(&extendedOutputsSpec));
     }
 
     {
-        auto [prefix, outputsSpec] = OutputsSpec::parse("foo^*");
+        auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse("foo^*");
         ASSERT_EQ(prefix, "foo");
-        ASSERT_TRUE(std::get_if<AllOutputs>(&outputsSpec));
+        ASSERT_TRUE(std::get_if<AllOutputs>(&extendedOutputsSpec));
     }
 
     {
-        auto [prefix, outputsSpec] = OutputsSpec::parse("foo^out");
+        auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse("foo^out");
         ASSERT_EQ(prefix, "foo");
-        ASSERT_TRUE(std::get<OutputNames>(outputsSpec) == OutputNames({"out"}));
+        ASSERT_TRUE(std::get<OutputNames>(extendedOutputsSpec) == OutputNames({"out"}));
     }
 
     {
-        auto [prefix, outputsSpec] = OutputsSpec::parse("foo^out,bin");
+        auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse("foo^out,bin");
         ASSERT_EQ(prefix, "foo");
-        ASSERT_TRUE(std::get<OutputNames>(outputsSpec) == OutputNames({"out", "bin"}));
+        ASSERT_TRUE(std::get<OutputNames>(extendedOutputsSpec) == OutputNames({"out", "bin"}));
     }
 
     {
-        auto [prefix, outputsSpec] = OutputsSpec::parse("foo^bar^out,bin");
+        auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse("foo^bar^out,bin");
         ASSERT_EQ(prefix, "foo^bar");
-        ASSERT_TRUE(std::get<OutputNames>(outputsSpec) == OutputNames({"out", "bin"}));
+        ASSERT_TRUE(std::get<OutputNames>(extendedOutputsSpec) == OutputNames({"out", "bin"}));
     }
 
     {
-        auto [prefix, outputsSpec] = OutputsSpec::parse("foo^&*()");
+        auto [prefix, extendedOutputsSpec] = ExtendedOutputsSpec::parse("foo^&*()");
         ASSERT_EQ(prefix, "foo^&*()");
-        ASSERT_TRUE(std::get_if<DefaultOutputs>(&outputsSpec));
+        ASSERT_TRUE(std::get_if<DefaultOutputs>(&extendedOutputsSpec));
     }
 }
 
diff --git a/src/nix/bundle.cc b/src/nix/bundle.cc
index 74a7973b0..a09dadff4 100644
--- a/src/nix/bundle.cc
+++ b/src/nix/bundle.cc
@@ -75,10 +75,10 @@ struct CmdBundle : InstallableCommand
 
         auto val = installable->toValue(*evalState).first;
 
-        auto [bundlerFlakeRef, bundlerName, outputsSpec] = parseFlakeRefWithFragmentAndOutputsSpec(bundler, absPath("."));
+        auto [bundlerFlakeRef, bundlerName, extendedOutputsSpec] = parseFlakeRefWithFragmentAndExtendedOutputsSpec(bundler, absPath("."));
         const flake::LockFlags lockFlags{ .writeLockFile = false };
         InstallableFlake bundler{this,
-            evalState, std::move(bundlerFlakeRef), bundlerName, outputsSpec,
+            evalState, std::move(bundlerFlakeRef), bundlerName, extendedOutputsSpec,
             {"bundlers." + settings.thisSystem.get() + ".default",
              "defaultBundler." + settings.thisSystem.get()
             },
diff --git a/src/nix/profile.cc b/src/nix/profile.cc
index 346c4e117..32364e720 100644
--- a/src/nix/profile.cc
+++ b/src/nix/profile.cc
@@ -22,7 +22,7 @@ struct ProfileElementSource
     // FIXME: record original attrpath.
     FlakeRef resolvedRef;
     std::string attrPath;
-    OutputsSpec outputs;
+    ExtendedOutputsSpec outputs;
 
     bool operator < (const ProfileElementSource & other) const
     {
@@ -126,7 +126,7 @@ struct ProfileManifest
                         parseFlakeRef(e[sOriginalUrl]),
                         parseFlakeRef(e[sUrl]),
                         e["attrPath"],
-                        e["outputs"].get<OutputsSpec>()
+                        e["outputs"].get<ExtendedOutputsSpec>()
                     };
                 }
                 elements.emplace_back(std::move(element));
@@ -308,12 +308,12 @@ struct CmdProfileInstall : InstallablesCommand, MixDefaultProfile
 
             auto & [res, info] = builtPaths[installable.get()];
 
-            if (info.originalRef && info.resolvedRef && info.attrPath && info.outputsSpec) {
+            if (info.originalRef && info.resolvedRef && info.attrPath && info.extendedOutputsSpec) {
                 element.source = ProfileElementSource {
                     .originalRef = *info.originalRef,
                     .resolvedRef = *info.resolvedRef,
                     .attrPath = *info.attrPath,
-                    .outputs = *info.outputsSpec,
+                    .outputs = *info.extendedOutputsSpec,
                 };
             }
 
@@ -497,7 +497,7 @@ struct CmdProfileUpgrade : virtual SourceExprCommand, MixDefaultProfile, MixProf
                     .originalRef = installable->flakeRef,
                     .resolvedRef = *info.resolvedRef,
                     .attrPath = *info.attrPath,
-                    .outputs = installable->outputsSpec,
+                    .outputs = installable->extendedOutputsSpec,
                 };
 
                 installables.push_back(installable);