diff --git a/ci/linux/build-x86_64-debug.sh b/ci/linux/build-x86_64-debug.sh
index d62f0c4194..1691b3884f 100755
--- a/ci/linux/build-x86_64-debug.sh
+++ b/ci/linux/build-x86_64-debug.sh
@@ -30,7 +30,7 @@ cd "$ZIGDIR"
 echo "building stage3-debug with zig version $($OLD_ZIG version)"
 
 "$OLD_ZIG" build \
-  --prefix stage3
+  --prefix stage3 \
   --search-prefix "$DEPS_LOCAL" \
   --zig-lib-dir lib \
   -Denable-stage1 \