diff --git a/include/flatbuffers/util.h b/include/flatbuffers/util.h
index 4292c5a25..b6bc78ad5 100644
--- a/include/flatbuffers/util.h
+++ b/include/flatbuffers/util.h
@@ -22,6 +22,7 @@
 #include <string>
 #include <sstream>
 #include <stdlib.h>
+#include <assert.h>
 #ifdef _WIN32
 #include <direct.h>
 #else