diff --git a/pkgs/development/python-modules/pytest-xdist/setup-hook.sh b/pkgs/development/python-modules/pytest-xdist/setup-hook.sh
index 8bba79ca3360..877fcf26d0cf 100644
--- a/pkgs/development/python-modules/pytest-xdist/setup-hook.sh
+++ b/pkgs/development/python-modules/pytest-xdist/setup-hook.sh
@@ -1,7 +1,10 @@
 pytestXdistHook() {
-    pytestFlagsArray+=("--numprocesses=$NIX_BUILD_CORES" "--forked" )
+    pytestFlagsArray+=(
+        "--numprocesses=$NIX_BUILD_CORES"
+        "--forked"
+    )
 }
 
 if [ -z "${dontUsePytestXdist-}" ] && [ -z "${dontUsePytestCheck-}" ]; then
-    addEnvHooks "$hostOffset" pytestXdistHook
+    preDistPhases+=" pytestXdistHook"
 fi