diff --git a/libs/rs/rsMatrix.cpp b/libs/rs/rsMatrix.cpp
index 7d22ae0095812..e68d5ac504395 100644
--- a/libs/rs/rsMatrix.cpp
+++ b/libs/rs/rsMatrix.cpp
@@ -17,6 +17,7 @@
 #include "rsMatrix.h"
 
 #include "stdlib.h"
+#include "string.h"
 #include "math.h"
 
 #include <utils/Log.h>