diff --git a/Makefile b/Makefile
index 72fd89a..c626646 100644
--- a/Makefile
+++ b/Makefile
@@ -8,13 +8,15 @@ OBJS += ./imgui/imgui_draw.o
 OBJS += ./imgui/imgui_demo.o
 OBJS += ./imgui/imgui_widgets.o
 
+CXXFLAGS=-O2
+
 UNAME_S := $(shell uname -s)
 
 ifeq ($(UNAME_S), Linux) #LINUX
 	ECHO_MESSAGE = "Linux"
 
 	OUTPUTNAME = cimgui.so
-	CXXFLAGS = -I./imgui/
+	CXXFLAGS += -I./imgui/
 	CXXFLAGS += -Wall
 	CXXFLAGS += -shared -fPIC
 	CFLAGS = $(CXXFLAGS)
@@ -24,7 +26,7 @@ ifeq ($(UNAME_S), Darwin) #APPLE
 	ECHO_MESSAGE = "macOS"
 
 	OUTPUTNAME = cimgui.dylib
-	CXXFLAGS = -I/usr/local/include
+	CXXFLAGS += -I/usr/local/include
 	CXXFLAGS += -Wall
 	LINKFLAGS = -dynamiclib
 	CFLAGS = $(CXXFLAGS)
@@ -34,7 +36,7 @@ ifeq ($(OS), Windows_NT)
 	ECHO_MESSAGE = "Windows"
 
 	OUTPUTNAME = cimgui.dll
-	CXXFLAGS = -I./imgui/
+	CXXFLAGS += -I./imgui/
 	CXXFLAGS += -Wall
 	CXXFLAGS += -shared
 	LINKFLAGS = -limm32