diff --git a/Makefile b/Makefile
index 40de98ffe..ad2da4cf6 100644
--- a/Makefile
+++ b/Makefile
@@ -16,27 +16,31 @@ export CGO_CFLAGS CGO_LDFLAGS PATH
 
 default: test
 
-dev: libucl
+dev: config/y.go libucl
 	@sh -c "$(CURDIR)/scripts/build.sh"
 
 libucl: vendor/libucl/$(LIBUCL_NAME)
 
-test: libucl
+test: config/y.go libucl
 	TF_ACC= go test $(TEST) $(TESTARGS) -timeout=10s
 
-testacc: libucl
+testacc: config/y.go libucl
 	@if [ "$(TEST)" = "./..." ]; then \
 		echo "ERROR: Set TEST to a specific package"; \
 		exit 1; \
 	fi
 	TF_ACC=1 go test $(TEST) -v $(TESTARGS)
 
-testrace: libucl
+testrace: config/y.go libucl
 	TF_ACC= go test -race $(TEST) $(TESTARGS)
 
 updatedeps:
 	go get -u -v ./...
 
+config/y.go: config/expr.y
+	cd config/ && \
+		go tool yacc -p "expr" expr.y
+
 vendor/libucl/libucl.a: vendor/libucl
 	cd vendor/libucl && \
 		cmake cmake/ && \