diff --git a/external.mk b/external.mk
index 7740dd7c..1660fee1 100644
--- a/external.mk
+++ b/external.mk
@@ -14,6 +14,6 @@ run:
 	@$(BINARIES_DIR)/qemu.sh
 
 .PHONY: run-menuconfig
-run-menuconfig:
+run-menuconfig: $(BUILD_DIR)/buildroot-config/mconf
 	CONFIG_="CONFIG_" BR2_CONFIG="$(BINARIES_DIR)/.config" \
 		$(BUILD_DIR)/buildroot-config/mconf $(BINARIES_DIR)/Config.in