diff --git a/Makefile b/Makefile
index 0d5c534..b570e8b 100644
--- a/Makefile
+++ b/Makefile
@@ -1,10 +1,10 @@
 CC ?= gcc
-CFLAGS_BENCH := -std=gnu99 -O3
-LFLAGS_BENCH := -lpng
-CFLAGS_CONV := -std=c99 -O3
+CFLAGS_BENCH ?= -std=gnu99 -O3
+LFLAGS_BENCH ?= -lpng
+CFLAGS_CONV ?= -std=c99 -O3
 
-TARGET_BENCH := qoibench
-TARGET_CONV := qoiconv
+TARGET_BENCH ?= qoibench
+TARGET_CONV ?= qoiconv
 
 all: $(TARGET_BENCH) $(TARGET_CONV)