diff --git a/target/linux/ramips/mt7621/target.mk b/target/linux/ramips/mt7621/target.mk
index 4acf16eaae..1929d41fc1 100644
--- a/target/linux/ramips/mt7621/target.mk
+++ b/target/linux/ramips/mt7621/target.mk
@@ -8,7 +8,7 @@ ARCH_PACKAGES:=ramips_1004kc
 FEATURES+=usb
 CPU_TYPE:=1004kc
 CPU_SUBTYPE:=dsp
-CFLAGS:=-pipe -mmt -mips32r2 -mtune=1004kc
+CFLAGS:=-Os -pipe -mmt -mips32r2 -mtune=1004kc
 
 define Target/Description
 	Build firmware images for Ralink MT7621 based boards.