diff --git a/package/network/utils/arptables/Makefile b/package/network/utils/arptables/Makefile
index 7f32ed1395..260824359a 100644
--- a/package/network/utils/arptables/Makefile
+++ b/package/network/utils/arptables/Makefile
@@ -31,7 +31,7 @@ define Package/arptables-legacy
 endef
 
 MAKE_FLAGS += \
-	COPT_FLAGS="$(TARGET_CFLAGS) -D__OPTIMIZE__=1" \
+	COPT_FLAGS="$(TARGET_CFLAGS) $(TARGET_CPPFLAGS) -D__OPTIMIZE__=1" \
 	KERNEL_DIR="$(LINUX_DIR)"
 
 define Package/arptables-legacy/install