diff --git a/pkgs/development/tools/misc/patchelf/setup-hook.sh b/pkgs/development/tools/misc/patchelf/setup-hook.sh
index bc1cddd4879c..576b9ca2103e 100644
--- a/pkgs/development/tools/misc/patchelf/setup-hook.sh
+++ b/pkgs/development/tools/misc/patchelf/setup-hook.sh
@@ -2,7 +2,7 @@
 # directories from the RPATH of every library or executable in every
 # output.
 
-fixupOutputHooks+=('if [ -z "$dontPatchELF" ]; then patchELF "$prefix"; fi')
+fixupOutputHooks+=('if [ -z "${dontPatchELF-}" ]; then patchELF "$prefix"; fi')
 
 patchELF() {
     local dir="$1"