diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index f1968e2..b0386f0 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -1813,7 +1813,7 @@
         ;
     test_structmembers *ob;
     const char *s = NULL;
-    Py_ssize_t string_len = 0;
+    int string_len = 0;
     ob = PyObject_New(test_structmembers, type);
     if (ob == NULL)
         return NULL;