diff --git a/src/libstore/build/derivation-goal.cc b/src/libstore/build/derivation-goal.cc
index 01da37df6..b2bb9da75 100644
--- a/src/libstore/build/derivation-goal.cc
+++ b/src/libstore/build/derivation-goal.cc
@@ -333,9 +333,9 @@ Goal::Co DerivationGoal::gaveUpOnSubstitution()
     /* The inputs must be built before we can build this goal. */
     inputDrvOutputs.clear();
     if (useDerivation) {
-        std::function<void(ref<SingleDerivedPath>, const DerivedPathMap<StringSet>::ChildNode &)> addWaiteeDerivedPath;
+        std::function<void(ref<const SingleDerivedPath>, const DerivedPathMap<StringSet>::ChildNode &)> addWaiteeDerivedPath;
 
-        addWaiteeDerivedPath = [&](ref<SingleDerivedPath> inputDrv, const DerivedPathMap<StringSet>::ChildNode & inputNode) {
+        addWaiteeDerivedPath = [&](ref<const SingleDerivedPath> inputDrv, const DerivedPathMap<StringSet>::ChildNode & inputNode) {
             if (!inputNode.value.empty())
                 addWaitee(worker.makeGoal(
                     DerivedPath::Built {
diff --git a/src/libstore/derived-path.cc b/src/libstore/derived-path.cc
index 1eef881de..3e3318965 100644
--- a/src/libstore/derived-path.cc
+++ b/src/libstore/derived-path.cc
@@ -170,7 +170,7 @@ void drvRequireExperiment(
 }
 
 SingleDerivedPath::Built SingleDerivedPath::Built::parse(
-    const StoreDirConfig & store, ref<SingleDerivedPath> drv,
+    const StoreDirConfig & store, ref<const SingleDerivedPath> drv,
     OutputNameView output,
     const ExperimentalFeatureSettings & xpSettings)
 {
@@ -182,7 +182,7 @@ SingleDerivedPath::Built SingleDerivedPath::Built::parse(
 }
 
 DerivedPath::Built DerivedPath::Built::parse(
-    const StoreDirConfig & store, ref<SingleDerivedPath> drv,
+    const StoreDirConfig & store, ref<const SingleDerivedPath> drv,
     OutputNameView outputsS,
     const ExperimentalFeatureSettings & xpSettings)
 {
@@ -201,7 +201,7 @@ static SingleDerivedPath parseWithSingle(
     return n == s.npos
         ? (SingleDerivedPath) SingleDerivedPath::Opaque::parse(store, s)
         : (SingleDerivedPath) SingleDerivedPath::Built::parse(store,
-            make_ref<SingleDerivedPath>(parseWithSingle(
+            make_ref<const SingleDerivedPath>(parseWithSingle(
                 store,
                 s.substr(0, n),
                 separator,
@@ -234,7 +234,7 @@ static DerivedPath parseWith(
     return n == s.npos
         ? (DerivedPath) DerivedPath::Opaque::parse(store, s)
         : (DerivedPath) DerivedPath::Built::parse(store,
-            make_ref<SingleDerivedPath>(parseWithSingle(
+            make_ref<const SingleDerivedPath>(parseWithSingle(
                 store,
                 s.substr(0, n),
                 separator,
diff --git a/src/libstore/derived-path.hh b/src/libstore/derived-path.hh
index 4ba3fb37d..23f9c2b30 100644
--- a/src/libstore/derived-path.hh
+++ b/src/libstore/derived-path.hh
@@ -45,7 +45,7 @@ struct SingleDerivedPath;
  * path of the given output name.
  */
 struct SingleDerivedPathBuilt {
-    ref<SingleDerivedPath> drvPath;
+    ref<const SingleDerivedPath> drvPath;
     OutputName output;
 
     /**
@@ -74,7 +74,7 @@ struct SingleDerivedPathBuilt {
      * @param xpSettings Stop-gap to avoid globals during unit tests.
      */
     static SingleDerivedPathBuilt parse(
-        const StoreDirConfig & store, ref<SingleDerivedPath> drvPath,
+        const StoreDirConfig & store, ref<const SingleDerivedPath> drvPath,
         OutputNameView outputs,
         const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
     nlohmann::json toJSON(Store & store) const;
@@ -172,7 +172,7 @@ static inline ref<SingleDerivedPath> makeConstantStorePathRef(StorePath drvPath)
  * output name.
  */
 struct DerivedPathBuilt {
-    ref<SingleDerivedPath> drvPath;
+    ref<const SingleDerivedPath> drvPath;
     OutputsSpec outputs;
 
     /**
@@ -201,7 +201,7 @@ struct DerivedPathBuilt {
      * @param xpSettings Stop-gap to avoid globals during unit tests.
      */
     static DerivedPathBuilt parse(
-        const StoreDirConfig & store, ref<SingleDerivedPath>,
+        const StoreDirConfig & store, ref<const SingleDerivedPath>,
         std::string_view,
         const ExperimentalFeatureSettings & xpSettings = experimentalFeatureSettings);
     nlohmann::json toJSON(Store & store) const;
diff --git a/src/nix/log.cc b/src/nix/log.cc
index 2c35ed803..6e23188db 100644
--- a/src/nix/log.cc
+++ b/src/nix/log.cc
@@ -35,7 +35,7 @@ struct CmdLog : InstallableCommand
         // For compat with CLI today, TODO revisit
         auto oneUp = std::visit(overloaded {
             [&](const DerivedPath::Opaque & bo) {
-                return make_ref<SingleDerivedPath>(bo);
+                return make_ref<const SingleDerivedPath>(bo);
             },
             [&](const DerivedPath::Built & bfd) {
                 return bfd.drvPath;