diff --git a/h_malloc.c b/h_malloc.c
index 67451bc..5cdd1ec 100644
--- a/h_malloc.c
+++ b/h_malloc.c
@@ -21,6 +21,10 @@
 #include "random.h"
 #include "util.h"
 
+#ifdef USE_PKEY
+#include <sys/mman.h>
+#endif
+
 #define SLAB_QUARANTINE (SLAB_QUARANTINE_RANDOM_LENGTH > 0 || SLAB_QUARANTINE_QUEUE_LENGTH > 0)
 #define REGION_QUARANTINE (REGION_QUARANTINE_RANDOM_LENGTH > 0 || REGION_QUARANTINE_QUEUE_LENGTH > 0)
 #define MREMAP_MOVE_THRESHOLD (32 * 1024 * 1024)