diff --git a/pkgs/development/python-modules/pytest-forked/setup-hook.sh b/pkgs/development/python-modules/pytest-forked/setup-hook.sh
index 88ccd0aac171..360ddfdfdaf5 100644
--- a/pkgs/development/python-modules/pytest-forked/setup-hook.sh
+++ b/pkgs/development/python-modules/pytest-forked/setup-hook.sh
@@ -1,7 +1,5 @@
 pytestForkedHook() {
-    pytestFlagsArray+=(
-        "--forked"
-    )
+    appendToVar pytestFlags "--forked"
 
     # Using --forked on darwin leads to crashes when fork safety is
     # enabled. This often happens when urllib tries to request proxy