diff --git a/Python/importdl.c b/Python/importdl.c
index 157257f..a086990 100644
--- a/Python/importdl.c
+++ b/Python/importdl.c
@@ -33,6 +33,11 @@
 /* If no dynamic linking is supported, this file still generates some code! */
 
 #include "Python.h"
+
+#ifdef HAVE_SYS_PARAM_H
+/* osdefs.h will define MAXPATHLEN if it's not already defined. */
+#include <sys/param.h>
+#endif
 #include "osdefs.h"
 #include "importdl.h"
 
@@ -89,10 +94,6 @@
 #define LONG_EXT ".dll"
 #endif
 
-#ifdef HAVE_SYS_PARAM_H
-#include <sys/param.h>
-#endif
-
 #if defined(__NetBSD__) && (NetBSD < 199712)
 #define DYNAMIC_LINK
 #define USE_SHLIB