diff --git a/tests/tests.yml b/tests/tests.yml
index fb2659f..8a4ba6b 100644
--- a/tests/tests.yml
+++ b/tests/tests.yml
@@ -36,16 +36,16 @@
         run: "VERSION={{ pybasever }} PYTHON=python{{ pybasever }}d X='-i test_check_probes' ./parallel.sh"
     - optimizedflags:
         dir: python/flags
-        run: "python{{ pybasever }} ./assertflags.py -O3"
+        run: "python{{ pybasever }} ./assertflags.py -O3 CFLAGS PY_BUILTIN_MODULE_CFLAGS PY_CFLAGS PY_CORE_CFLAGS PY_CFLAGS_NODIST PY_STDMODULE_CFLAGS"
     - debugflags:
         dir: python/flags
-        run: "python{{ pybasever }}d ./assertflags.py -O0"
+        run: "python{{ pybasever }}d ./assertflags.py -O0 CFLAGS PY_BUILTIN_MODULE_CFLAGS PY_CFLAGS PY_CORE_CFLAGS PY_CFLAGS_NODIST PY_STDMODULE_CFLAGS"
     - freethreadingflags:
         dir: python/flags
-        run: "python{{ pybasever }}t ./assertflags.py -O3"
+        run: "python{{ pybasever }}t ./assertflags.py -O3 CFLAGS PY_BUILTIN_MODULE_CFLAGS PY_CFLAGS PY_CORE_CFLAGS PY_CFLAGS_NODIST PY_STDMODULE_CFLAGS"
     - freethreadingdebugflags:
         dir: python/flags
-        run: "python{{ pybasever }}td ./assertflags.py -O0"
+        run: "python{{ pybasever }}td ./assertflags.py -O0 CFLAGS PY_BUILTIN_MODULE_CFLAGS PY_CFLAGS PY_CORE_CFLAGS PY_CFLAGS_NODIST PY_STDMODULE_CFLAGS"
     - marshalparser:
         dir: python/marshalparser
         run: "VERSION={{ pybasever }} SAMPLE=10 test_marshalparser_compatibility.sh"