diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 5a6097ef0ac5a6..8b2ce1a2cfd4bd 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -3185,11 +3185,11 @@ eval_eval_code_ex(PyObject *mod, PyObject *pos_args)
         globals,
         locals,
         c_args,
-        c_args_len,
+        (int)c_args_len,
         c_kwargs,
-        c_kwargs_len,
+        (int)c_kwargs_len,
         c_defaults,
-        c_defaults_len,
+        (int)c_defaults_len,
         kw_defaults,
         closure
     );