diff --git a/libretro/Makefile b/libretro/Makefile
index f4c086b..af28a62 100644
--- a/libretro/Makefile
+++ b/libretro/Makefile
@@ -732,8 +732,13 @@ ifneq (,$(findstring msvc,$(platform)))
 CFLAGS   += -MT
 CXXFLAGS += -MT
 endif
-CFLAGS   += -O2 -DNDEBUG
-CXXFLAGS += -O2 -DNDEBUG
+ifeq ($(platform), emscripten)
+   CFLAGS   += -O3 -DNDEBUG
+   CXXFLAGS += -O3 -DNDEBUG
+else
+   CFLAGS   += -O2 -DNDEBUG
+   CXXFLAGS += -O2 -DNDEBUG
+endif
 endif
 
 CORE_DIR = ..