diff --git a/Makefile b/Makefile
index 9747718..dcdfb2f 100644
--- a/Makefile
+++ b/Makefile
@@ -43,10 +43,10 @@ SDL_CONFIG ?= sdl2-config
 export SDL_CFLAGS := $(shell $(SDL_CONFIG) --cflags)
 export SDL_LDFLAGS := $(shell $(SDL_CONFIG) --libs)
 
-CPPFLAGS = -MD -MT $@ -MF $(@:%.o=%.d) $(SDL_CFLAGS) -Iexternal/libguisan/include -Isrc -Isrc/osdep -Isrc/threaddep -Isrc/include -Isrc/archivers -Iexternal/floppybridge/src -Iexternal/mt32emu/src -D_FILE_OFFSET_BITS=64
-CFLAGS=-pipe -Wno-shift-overflow -Wno-narrowing -fno-pie
+CPPFLAGS += -MD -MT $@ -MF $(@:%.o=%.d) $(SDL_CFLAGS) -Iexternal/libguisan/include -Isrc -Isrc/osdep -Isrc/threaddep -Isrc/include -Isrc/archivers -Iexternal/floppybridge/src -Iexternal/mt32emu/src -D_FILE_OFFSET_BITS=64
+CFLAGS += -pipe -Wno-shift-overflow -Wno-narrowing -fno-pie
 
-LDFLAGS = $(SDL_LDFLAGS) -lSDL2_image -lSDL2_ttf -lserialport -lportmidi -lguisan -Lexternal/libguisan/lib -lmt32emu -Lexternal/mt32emu
+LDFLAGS += $(SDL_LDFLAGS) -lSDL2_image -lSDL2_ttf -lserialport -lportmidi -lguisan -Lexternal/libguisan/lib -lmt32emu -Lexternal/mt32emu
 LDFLAGS += -Wl,-O1 -Wl,--hash-style=gnu -Wl,--as-needed -lpthread -lz -lpng -lrt -lFLAC -lmpg123 -ldl -lmpeg2convert -lmpeg2 -lstdc++fs -no-pie
 
 ifdef USE_OPENGL