diff --git a/config.sh b/config.sh
index 71017f664..97351f6e0 100644
--- a/config.sh
+++ b/config.sh
@@ -18,6 +18,15 @@ LIBWEBP_VERSION=1.2.0
 BZIP2_VERSION=1.0.8
 LIBXCB_VERSION=1.14
 
+function pyinst_fname_for_version {
+    local inst_ext=$(pyinst_ext_for_version $1)
+    if [ "${PLAT:-}" == "arm64" ]; then
+        echo "python-$1-macos11.${inst_ext}"
+    else
+        echo "python-$1-macosx$2.${inst_ext}"
+    fi
+}
+
 function pre_build {
     # Any stuff that you need to do before you start building the wheels
     # Runs in the root directory of this repository.