diff --git a/Modules/_ctypes/cfield.c b/Modules/_ctypes/cfield.c
index 0f69d74..de41571 100644
--- a/Modules/_ctypes/cfield.c
+++ b/Modules/_ctypes/cfield.c
@@ -251,10 +251,10 @@
 
 	if (bits)
 		result = PyString_FromFormat("<Field type=%s, ofs=%d:%d, bits=%d>",
-					     name, self->offset, size, bits);
+					     name, (int)self->offset, size, bits);
 	else
 		result = PyString_FromFormat("<Field type=%s, ofs=%d, size=%d>",
-					     name, self->offset, size);
+					     name, (int)self->offset, size);
 	return result;
 }