diff --git a/src/libfetchers/filtering-source-accessor.cc b/src/libfetchers/filtering-source-accessor.cc
index 29f0be3080e..8ad13b33416 100644
--- a/src/libfetchers/filtering-source-accessor.cc
+++ b/src/libfetchers/filtering-source-accessor.cc
@@ -61,6 +61,11 @@ std::pair<CanonPath, std::optional<std::string>> FilteringSourceAccessor::getFin
     return next->getFingerprint(prefix / path);
 }
 
+void FilteringSourceAccessor::invalidateCache(const CanonPath & path)
+{
+    next->invalidateCache(prefix / path);
+}
+
 void FilteringSourceAccessor::checkAccess(const CanonPath & path)
 {
     if (!isAllowed(path))
diff --git a/src/libfetchers/include/nix/fetchers/filtering-source-accessor.hh b/src/libfetchers/include/nix/fetchers/filtering-source-accessor.hh
index 396a184fe72..ed3fc56f676 100644
--- a/src/libfetchers/include/nix/fetchers/filtering-source-accessor.hh
+++ b/src/libfetchers/include/nix/fetchers/filtering-source-accessor.hh
@@ -52,6 +52,8 @@ struct FilteringSourceAccessor : SourceAccessor
 
     std::pair<CanonPath, std::optional<std::string>> getFingerprint(const CanonPath & path) override;
 
+    void invalidateCache(const CanonPath & path) override;
+
     /**
      * Call `makeNotAllowedError` to throw a `RestrictedPathError`
      * exception if `isAllowed()` returns `false` for `path`.
diff --git a/src/libflake/flake.cc b/src/libflake/flake.cc
index be3b667d2da..9dab20c5c10 100644
--- a/src/libflake/flake.cc
+++ b/src/libflake/flake.cc
@@ -876,6 +876,8 @@ lockFlake(const Settings & settings, EvalState & state, const FlakeRef & topRef,
                                 CanonPath((topRef.subdir == "" ? "" : topRef.subdir + "/") + "flake.lock"),
                                 newLockFileS,
                                 commitMessage);
+
+                            flake.lockFilePath().invalidateCache();
                         }
 
                         /* Rewriting the lockfile changed the top-level
diff --git a/src/libutil/include/nix/util/posix-source-accessor.hh b/src/libutil/include/nix/util/posix-source-accessor.hh
index c3733119bff..7ff7ee9fdee 100644
--- a/src/libutil/include/nix/util/posix-source-accessor.hh
+++ b/src/libutil/include/nix/util/posix-source-accessor.hh
@@ -80,6 +80,8 @@ public:
         return trackLastModified ? std::optional{mtime} : std::nullopt;
     }
 
+    void invalidateCache(const CanonPath & path) override;
+
 private:
 
     /**
diff --git a/src/libutil/include/nix/util/source-accessor.hh b/src/libutil/include/nix/util/source-accessor.hh
index ee09b182b7b..e1de9ece7f3 100644
--- a/src/libutil/include/nix/util/source-accessor.hh
+++ b/src/libutil/include/nix/util/source-accessor.hh
@@ -213,6 +213,11 @@ struct SourceAccessor : std::enable_shared_from_this<SourceAccessor>
     {
         return std::nullopt;
     }
+
+    /**
+     * Invalidate any cached value the accessor may have for the specified path.
+     */
+    virtual void invalidateCache(const CanonPath & path) {}
 };
 
 /**
diff --git a/src/libutil/include/nix/util/source-path.hh b/src/libutil/include/nix/util/source-path.hh
index 08f9fe580b0..4597de1ff46 100644
--- a/src/libutil/include/nix/util/source-path.hh
+++ b/src/libutil/include/nix/util/source-path.hh
@@ -114,6 +114,11 @@ struct SourcePath
         return {accessor, accessor->resolveSymlinks(path, mode)};
     }
 
+    void invalidateCache() const
+    {
+        accessor->invalidateCache(path);
+    }
+
     friend class std::hash<nix::SourcePath>;
 };
 
diff --git a/src/libutil/mounted-source-accessor.cc b/src/libutil/mounted-source-accessor.cc
index 4122fc78c12..73ad5c9a94a 100644
--- a/src/libutil/mounted-source-accessor.cc
+++ b/src/libutil/mounted-source-accessor.cc
@@ -99,6 +99,12 @@ struct MountedSourceAccessorImpl : MountedSourceAccessor
         auto [accessor, subpath] = resolve(path);
         return accessor->getFingerprint(subpath);
     }
+
+    void invalidateCache(const CanonPath & path) override
+    {
+        auto [accessor, subpath] = resolve(path);
+        accessor->invalidateCache(subpath);
+    }
 };
 
 ref<MountedSourceAccessor> makeMountedSourceAccessor(std::map<CanonPath, ref<SourceAccessor>> mounts)
diff --git a/src/libutil/posix-source-accessor.cc b/src/libutil/posix-source-accessor.cc
index ccb9c89d94e..86f28def0d4 100644
--- a/src/libutil/posix-source-accessor.cc
+++ b/src/libutil/posix-source-accessor.cc
@@ -85,11 +85,11 @@ bool PosixSourceAccessor::pathExists(const CanonPath & path)
     return nix::pathExists(makeAbsPath(path).string());
 }
 
+using Cache = boost::concurrent_flat_map<Path, std::optional<PosixStat>>;
+static Cache cache;
+
 std::optional<PosixStat> PosixSourceAccessor::cachedLstat(const CanonPath & path)
 {
-    using Cache = boost::concurrent_flat_map<Path, std::optional<PosixStat>>;
-    static Cache cache;
-
     // Note: we convert std::filesystem::path to Path because the
     // former is not hashable on libc++.
     Path absPath = makeAbsPath(path).string();
@@ -106,6 +106,11 @@ std::optional<PosixStat> PosixSourceAccessor::cachedLstat(const CanonPath & path
     return st;
 }
 
+void PosixSourceAccessor::invalidateCache(const CanonPath & path)
+{
+    cache.erase(makeAbsPath(path).string());
+}
+
 std::optional<SourceAccessor::Stat> PosixSourceAccessor::maybeLstat(const CanonPath & path)
 {
     if (auto parent = path.parent())
diff --git a/src/libutil/union-source-accessor.cc b/src/libutil/union-source-accessor.cc
index d19400303e2..dfe81f635cd 100644
--- a/src/libutil/union-source-accessor.cc
+++ b/src/libutil/union-source-accessor.cc
@@ -90,6 +90,12 @@ struct UnionSourceAccessor : SourceAccessor
         }
         return {path, std::nullopt};
     }
+
+    void invalidateCache(const CanonPath & path) override
+    {
+        for (auto & accessor : accessors)
+            accessor->invalidateCache(path);
+    }
 };
 
 ref<SourceAccessor> makeUnionSourceAccessor(std::vector<ref<SourceAccessor>> && accessors)