diff --git a/src/libfetchers/fetchers.cc b/src/libfetchers/fetchers.cc
index 087880ebe..294960678 100644
--- a/src/libfetchers/fetchers.cc
+++ b/src/libfetchers/fetchers.cc
@@ -419,7 +419,7 @@ namespace nlohmann {
 using namespace nix;
 
 fetchers::PublicKey adl_serializer<fetchers::PublicKey>::from_json(const json & json) {
-    fetchers::PublicKey res = {  };
+    fetchers::PublicKey res = { };
     if (auto type = optionalValueAt(json, "type"))
         res.type = getString(*type);
 
diff --git a/src/libflake/flake/flake.cc b/src/libflake/flake/flake.cc
index 93d528d61..6f47b5992 100644
--- a/src/libflake/flake/flake.cc
+++ b/src/libflake/flake/flake.cc
@@ -950,10 +950,20 @@ std::optional<Fingerprint> LockedFlake::getFingerprint(ref<Store> store) const
     auto fingerprint = flake.lockedRef.input.getFingerprint(store);
     if (!fingerprint) return std::nullopt;
 
+    *fingerprint += fmt(";%s;%s", flake.lockedRef.subdir, lockFile);
+
+    /* Include revCount and lastModified because they're not
+       necessarily implied by the content fingerprint (e.g. for
+       tarball flakes) but can influence the evaluation result. */
+    if (auto revCount = flake.lockedRef.input.getRevCount())
+        *fingerprint += fmt(";revCount=%d", *revCount);
+    if (auto lastModified = flake.lockedRef.input.getLastModified())
+        *fingerprint += fmt(";lastModified=%d", *lastModified);
+
     // FIXME: as an optimization, if the flake contains a lock file
     // and we haven't changed it, then it's sufficient to use
     // flake.sourceInfo.storePath for the fingerprint.
-    return hashString(HashAlgorithm::SHA256, fmt("%s;%s;%s", *fingerprint, flake.lockedRef.subdir, lockFile));
+    return hashString(HashAlgorithm::SHA256, *fingerprint);
 }
 
 Flake::~Flake() { }