diff --git a/libraries/liblmdb/midl.c b/libraries/liblmdb/midl.c
index 42c809f..57f1e04 100644
--- a/libraries/liblmdb/midl.c
+++ b/libraries/liblmdb/midl.c
@@ -18,6 +18,7 @@
 #include <limits.h>
 #include <string.h>
 #include <stdlib.h>
+#include <errno.h>
 #include <sys/types.h>
 #include <assert.h>
 #include "midl.h"