diff --git a/external/easylogging++/easylogging++.h b/external/easylogging++/easylogging++.h
index 03d62bfb6..0b65461bc 100644
--- a/external/easylogging++/easylogging++.h
+++ b/external/easylogging++/easylogging++.h
@@ -127,6 +127,8 @@
 #endif
 #if defined(__EMSCRIPTEN__)
 #  define ELPP_OS_EMSCRIPTEN 1
+#else
+#  define ELPP_OS_EMSCRIPTEN 0
 #endif
 #if (defined(__DragonFly__))
 #   define ELPP_OS_DRAGONFLY 1