diff --git a/src/d_main.cpp b/src/d_main.cpp
index 87ed27e4c..ea2f4e22f 100644
--- a/src/d_main.cpp
+++ b/src/d_main.cpp
@@ -77,6 +77,7 @@
 #include "doomstat.h"
 #include "m_random.h" // P_ClearRandom
 #include "acs/interface.h"
+#include <cstring>
 
 #ifdef CMAKECONFIG
 #include "config.h"