diff --git a/nix/update-inputs.sh b/nix/update-inputs.sh
index 6db18606..b5aeff2e 100755
--- a/nix/update-inputs.sh
+++ b/nix/update-inputs.sh
@@ -18,7 +18,7 @@ if [ "$SUB_REV" != "$CRT_REV" ]; then
   jq <flake.lock 'del(.nodes.wlroots.original.rev)' | sponge flake.lock
 
   # fix revision in wlroots.wrap
-  sed -Ei "s/[a-z0-9]{40}/$CRT_REV/g" subprojects/wlroots.wrap
+  sed -Ei "s/[a-z0-9]{40}/$SUB_REV/g" subprojects/wlroots.wrap
 else
   echo "wlroots is up to date!"
 fi