1 files changed, 12 insertions, 0 deletions
diff --git a/tests/flakes/check.sh b/tests/flakes/check.sh
index 34b82c61c..0433e5335 100644
--- a/tests/flakes/check.sh
+++ b/tests/flakes/check.sh
@@ -27,6 +27,18 @@ EOF
 
 cat > $flakeDir/flake.nix <<EOF
 {
+  outputs = { self, ... }: {
+    overlays.x86_64-linux.foo = final: prev: {
+    };
+  };
+}
+EOF
+
+checkRes=$(nix flake check $flakeDir 2>&1 && fail "nix flake check --all-systems should have failed" || true)
+echo "$checkRes" | grepQuiet "error: overlay is not a function, but a set instead"
+
+cat > $flakeDir/flake.nix <<EOF
+{
   outputs = { self }: {
     nixosModules.foo = {
       a.b.c = 123;