diff --git a/reactos/tools/sysreg/os_support.h b/reactos/tools/sysreg/os_support.h
index 0b40f7cbc4f..c67ffc6ad01 100644
--- a/reactos/tools/sysreg/os_support.h
+++ b/reactos/tools/sysreg/os_support.h
@@ -23,6 +23,7 @@
 #include <ctime>
 #include <vector>
 #include <cstdlib>
+#include <cstring>
 
 #ifndef _MSC_VER
 #include <sys/time.h>