diff --git a/Modules/_testcapimodule.c b/Modules/_testcapimodule.c
index 30a786c..3f3ed66 100644
--- a/Modules/_testcapimodule.c
+++ b/Modules/_testcapimodule.c
@@ -1952,7 +1952,7 @@
         return NULL;
     }
 
-    buffer = PyUnicode_AsUTF8AndSize(unicode, &utf8_len); 
+    buffer = PyUnicode_AsUTF8AndSize(unicode, &utf8_len);
     if (buffer == NULL) {
         return NULL;
     }
@@ -6406,7 +6406,7 @@
 
 static struct PyMemberDef heapctypewithnegativedict_members[] = {
     {"dictobj", T_OBJECT, offsetof(HeapCTypeWithDictObject, dict)},
-    {"__dictoffset__", T_PYSSIZET, -sizeof(void*), READONLY},
+    {"__dictoffset__", T_PYSSIZET, -(Py_ssize_t)sizeof(void*), READONLY},
     {NULL} /* Sentinel */
 };