diff --git a/target/linux/brcm63xx/image/Makefile b/target/linux/brcm63xx/image/Makefile
index 64711383cc..be96a5f16a 100644
--- a/target/linux/brcm63xx/image/Makefile
+++ b/target/linux/brcm63xx/image/Makefile
@@ -28,7 +28,7 @@ define trxalign/squashfs
 endef
 
 define Image/LimitName16
-	$(shell expr substr $(1) 1 16)
+$(shell expr substr "$(1)" 1 $$(expr length "$(1)"))
 endef
 
 define Image/Build/CFE