diff --git a/src/libexpr/flake/flake.cc b/src/libexpr/flake/flake.cc
index cc9be1336..105e76bc6 100644
--- a/src/libexpr/flake/flake.cc
+++ b/src/libexpr/flake/flake.cc
@@ -341,7 +341,6 @@ LockedFlake lockFlake(
 
         debug("old lock file: %s", oldLockFile);
 
-        // FIXME: check whether all overrides are used.
         std::map<InputPath, FlakeInput> overrides;
         std::set<InputPath> overridesUsed, updatesUsed;