diff --git a/pkgs/test/stdenv/gcc-stageCompare.nix b/pkgs/test/stdenv/gcc-stageCompare.nix
index e5c2ed5921b307..e06a5ecb315fae 100644
--- a/pkgs/test/stdenv/gcc-stageCompare.nix
+++ b/pkgs/test/stdenv/gcc-stageCompare.nix
@@ -14,6 +14,8 @@
 }:
 
 assert stdenv.cc.isGNU;
+assert lib.assertMsg (pkgs.gcc-unwrapped ? checksum) "No `checksum` output in `gcc-unwrapped` see conditional in `gcc/common/checksum.nix`";
+
 with pkgs;
 # rebuild gcc using the "final" stdenv
 let gcc-stageCompare = (gcc-unwrapped.override {