diff --git a/src/Makefile b/src/Makefile
index 5142282..4c0dbb8 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -3,7 +3,7 @@ STRIP = strip
 
 CFLAGS = -O3 -mtune=native -march=native
-CFLAGS += -Ilib
+override CFLAGS += -Ilib
 LDFLAGS = -lm
 
 SFLAGS = --strip-all