diff --git a/lib/libspl/include/sys/param.h b/lib/libspl/include/sys/param.h
index 4090cefe87..9f362dd8b5 100644
--- a/lib/libspl/include/sys/param.h
+++ b/lib/libspl/include/sys/param.h
@@ -57,6 +57,8 @@
 #define	MAXUID		UINT32_MAX	/* max user id */
 #define	MAXPROJID	MAXUID		/* max project id */
 
+#ifndef	PAGESIZE
 #define	PAGESIZE	(sysconf(_SC_PAGESIZE))
+#endif /* PAGESIZE */
 
 #endif