diff --git a/pkgs/build-support/setup-hooks/make-wrapper.sh b/pkgs/build-support/setup-hooks/make-wrapper.sh
index 086875976d3..4f55493ae48 100644
--- a/pkgs/build-support/setup-hooks/make-wrapper.sh
+++ b/pkgs/build-support/setup-hooks/make-wrapper.sh
@@ -22,7 +22,7 @@ makeWrapper() {
     local original=$1
     local wrapper=$2
     local params varName value command separator n fileNames
-    local argv0 flagsBefore flags
+    local argv0 flagsBefore flags extraFlagsArray
 
     mkdir -p "$(dirname $wrapper)"