diff --git a/src/py_build_cmake/config/quirks.py b/src/py_build_cmake/config/quirks.py
index a27709c..5e1b2c1 100644
--- a/src/py_build_cmake/config/quirks.py
+++ b/src/py_build_cmake/config/quirks.py
@@ -183,7 +183,7 @@ def config_quirks_mac(config: ValueReference):
     archflags = os.getenv("ARCHFLAGS")
     if not archflags:
         return
-    archs = tuple(re.findall(r"-arch +(\S+)", archflags))
+    archs = list(re.findall(r"-arch +(\S+)", archflags))
     if not archs:
         logger.warning(
             "ARCHFLAGS was set, but its value was not valid, so I'm ignoring it"