diff --git a/Modules/_ctypes/callproc.c b/Modules/_ctypes/callproc.c
index 63f3c21784d..ff2a7da4246 100644
--- a/Modules/_ctypes/callproc.c
+++ b/Modules/_ctypes/callproc.c
@@ -488,7 +488,7 @@ PyCArg_repr(PyCArgObject *self)
 #ifdef MS_WIN32
             "<cparam '%c' (%I64d)>",
 #else
-            "<cparam '%c' (%qd)>",
+            "<cparam '%c' (%lld)>",
 #endif
             self->tag, self->value.q);
         break;