diff --git a/src/server.h b/src/server.h
index 9d187e269..cb5ce5a3b 100644
--- a/src/server.h
+++ b/src/server.h
@@ -57,6 +57,7 @@
 #include <memory>
 #include <set>
 #include <map>
+#include <string>
 #ifdef __cplusplus
 extern "C" {
 #include <lua.h>