diff --git a/quantum/quantum.h b/quantum/quantum.h
index 36399736a9a..e41542e4afc 100644
--- a/quantum/quantum.h
+++ b/quantum/quantum.h
@@ -57,6 +57,7 @@
 #include <stddef.h>
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
 
 #ifdef DEFERRED_EXEC_ENABLE
 #    include "deferred_exec.h"