diff --git a/tuple/keydef.c b/tuple/keydef.c
index 4e33de9..753b698 100644
--- a/tuple/keydef.c
+++ b/tuple/keydef.c
@@ -31,6 +31,7 @@
 
 #include <assert.h>
 #include <stdint.h>
+#include <string.h>
 #include <lua.h>
 #include <lauxlib.h>
 #include <tarantool/module.h>