diff --git a/Makefile b/Makefile
index 92899c8..e28ebaa 100644
--- a/Makefile
+++ b/Makefile
@@ -1,11 +1,12 @@
 SHELL = /bin/bash
 TARGET = jumpforth
 SOURCES = $(TARGET).S
+EXTRA_DEPS = startup.4th
 
 all: $(TARGET)
 
-$(TARGET): $(SOURCES) startup.4th
-	gcc -m32 -nostdlib -static -o $@ $<
+$(TARGET): $(SOURCES) $(EXTRA_DEPS)
+	gcc -m32 -nostdlib -static -o $@ $(filter-out $(EXTRA_DEPS),$^)
 
 clean: test-clean
 	$(RM) $(TARGET)
@@ -18,6 +19,14 @@ test: $(TEST_RESULTS)
 test-clean:
 	$(RM) $(TEST_RESULTS)
 
+test-refresh: $(TEST_RESULTS)
+	@for act in $^; do \
+	   exp="$${act%.act}.exp"; \
+	   if ! diff -q "$$exp" "$$act" >/dev/null; then \
+	     echo "Refreshing $$exp"; cp -- "$$act" "$$exp"; \
+	   fi; \
+	 done
+
 .PHONY: $(TEST_RESULTS)
 $(TEST_RESULTS): %.act: %.4th $(TARGET)
 	@printf '%s … ' $(notdir $<) && \