diff --git a/Makefile b/Makefile
index b09a137..b2bf0bd 100644
--- a/Makefile
+++ b/Makefile
@@ -21,7 +21,7 @@ ifeq     ($(DEBUG),true)
   CXXFLAGS += -g -pg
 else
   # release flags
-  CXXFLAGS += -O2
+  CXXFLAGS += -Ofast
 endif
 ifeq    ($(STATIC),true)
   # static links