diff --git a/games/just_do_GGJ2015/src/makefile b/games/just_do_GGJ2015/src/makefile
index 32bee4dc1..4c36b154f 100644
--- a/games/just_do_GGJ2015/src/makefile
+++ b/games/just_do_GGJ2015/src/makefile
@@ -72,7 +72,7 @@ else
     CFLAGS = -O2 -Wall -std=c99
 endif
 ifeq ($(PLATFORM),PLATFORM_WEB)
-    CFLAGS = -O2 -Wall -std=c99 -s USE_GLFW=3 
+    CFLAGS = -O1 -Wall -std=c99 -s USE_GLFW=3 
     #-s ASSERTIONS=1 --preload-file resources
     #-s ALLOW_MEMORY_GROWTH=1   # to allow memory resizing
     #-s TOTAL_MEMORY=16777216   # to specify heap memory size (default = 16MB)