diff --git a/src/script/hydra-eval-jobset b/src/script/hydra-eval-jobset
index 7a9af09f..ad757771 100755
--- a/src/script/hydra-eval-jobset
+++ b/src/script/hydra-eval-jobset
@@ -644,7 +644,7 @@ sub checkJobsetWrapped {
     # Hash the arguments to hydra-eval-jobs and check the
     # JobsetInputHashes to see if the previous evaluation had the same
     # inputs.  If so, bail out.
-    my @args = ($jobset->nixexprinput, $jobset->nixexprpath, inputsToArgs($inputInfo));
+    my @args = ($jobset->nixexprinput // "", $jobset->nixexprpath // "", inputsToArgs($inputInfo));
     my $argsHash = sha256_hex("@args");
     my $prevEval = getPrevJobsetEval($db, $jobset, 0);
     if (defined $prevEval && $prevEval->hash eq $argsHash && !$dryRun && !$jobset->forceeval && $prevEval->flake eq $flakeRef) {