diff --git a/libretroshare/src/util/rsid.h b/libretroshare/src/util/rsid.h
index 5a6cd5eb0..b560a7466 100644
--- a/libretroshare/src/util/rsid.h
+++ b/libretroshare/src/util/rsid.h
@@ -30,6 +30,7 @@
 
 #include <stdexcept>
 #include <string>
+#include <string.h>
 #include <stdint.h>
 #include <util/rsrandom.h>