diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 3d476b0..2787164 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -312,8 +312,7 @@
 #endif /* UNION_WAIT */
 
 /* Issue #1983: pid_t can be longer than a C long on some systems */
-#ifdef SIZEOF_PID_T
-#if SIZEOF_PID_T == SIZEOF_INT
+#if !defined(SIZEOF_PID_T) || SIZEOF_PID_T == SIZEOF_INT
 #define PARSE_PID "i"
 #define PyLong_FromPid PyInt_FromLong
 #define PyLong_AsPid PyInt_AsLong
@@ -327,7 +326,6 @@
 #define PyLong_AsPid PyInt_AsLongLong
 #else
 #error "sizeof(pid_t) is neither sizeof(int), sizeof(long) or sizeof(long long)"
-#endif
 #endif /* SIZEOF_PID_T */
 
 /* Don't use the "_r" form if we don't need it (also, won't have a