diff --git a/libs/io/source/file_stream.cpp b/libs/io/source/file_stream.cpp
index 5e0a5b7e..01796abf 100644
--- a/libs/io/source/file_stream.cpp
+++ b/libs/io/source/file_stream.cpp
@@ -41,7 +41,11 @@ namespace psemek::io
 #else
 		char const * fopen_read_mode()
 		{
+#ifdef __EMSCRIPTEN__
+			return "r+b";
+#else
 			return "rb";
+#endif
 		}
 
 		char const * fopen_write_mode(unsigned flags)