diff -Naur p11-kit-0.20.2/common/compat.c p11-kit-0.20.2-new/common/compat.c
--- p11-kit-0.20.2/common/compat.c	2013-10-14 14:45:10.000000000 +0200
+++ p11-kit-0.20.2-new/common/compat.c	2014-02-12 21:28:03.000000000 +0100
@@ -218,7 +218,7 @@
 
 	map->size = sb->st_size;
 	map->data = mmap (NULL, map->size, PROT_READ, MAP_PRIVATE, map->fd, 0);
-	if (map->data == NULL) {
+	if (map->data == MAP_FAILED) {
 		close (map->fd);
 		free (map);
 		return NULL;