diff --git a/Makefile b/Makefile
index 2e6d53b..98ee172 100644
--- a/Makefile
+++ b/Makefile
@@ -4,9 +4,9 @@ PREFIX    = /usr/local
 MANPREFIX = $(PREFIX)/share/man
 
 CC       = gcc
-CFLAGS   = -std=c99 -Wall -pedantic -O2
+CFLAGS  += -std=c99 -Wall -pedantic -O2
 CPPFLAGS = -I$(PREFIX)/include -D_XOPEN_SOURCE=500 -DHAVE_GIFLIB
-LDFLAGS  = -L$(PREFIX)/lib
+LDFLAGS += -L$(PREFIX)/lib
 LIBS     = -lX11 -lImlib2 -lgif
 
 SRC = commands.c exif.c image.c main.c options.c thumbs.c util.c window.c