diff --git a/.travis.yml b/.travis.yml
index 639a68b..eb3042d 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,7 @@ sudo: required
 services:
   - docker
 go:
-  - 1.10.x
+  - 1.11.x
 before_install:
   - go get golang.org/x/lint/golint
   - go get honnef.co/go/tools/cmd/staticcheck
diff --git a/basic.mk b/basic.mk
index 96192f8..78f98ce 100644
--- a/basic.mk
+++ b/basic.mk
@@ -1,3 +1,6 @@
+# Set the shell
+SHELL := /bin/bash
+
 # Set an output prefix, which is the local directory if not specified
 PREFIX?=$(shell pwd)
 
@@ -56,12 +59,16 @@ all: clean build fmt lint test staticcheck vet install ## Runs a clean, build, f
 .PHONY: fmt
 fmt: ## Verifies all files have been `gofmt`ed.
 	@echo "+ $@"
-	@gofmt -s -l . | grep -v '.pb.go:' | grep -v vendor | tee /dev/stderr
+	@if [[ ! -z "$(shell gofmt -s -l . | grep -v '.pb.go' | grep -v '.twirp.go' | grep -v 'bindata.go' | grep -v vendor | tee /dev/stderr)" ]]; then \
+		exit 1; \
+	fi
 
 .PHONY: lint
 lint: ## Verifies `golint` passes.
 	@echo "+ $@"
-	@golint ./... | grep -v '.pb.go:' | grep -v vendor | tee /dev/stderr
+	@if [[ ! -z "$(shell golint ./... | grep -v '.pb.go:' | grep -v '.twirp.go:' | grep -v vendor | tee /dev/stderr)" ]]; then \
+		exit 1; \
+	fi
 
 .PHONY: test
 test: prebuild ## Runs the go tests.
@@ -71,12 +78,16 @@ test: prebuild ## Runs the go tests.
 .PHONY: vet
 vet: ## Verifies `go vet` passes.
 	@echo "+ $@"
-	@$(GO) vet $(shell $(GO) list ./... | grep -v vendor) | grep -v '.pb.go:' | tee /dev/stderr
+	@if [[ ! -z "$(shell $(GO) vet $(shell $(GO) list ./... | grep -v vendor) | tee /dev/stderr)" ]]; then \
+		exit 1; \
+	fi
 
 .PHONY: staticcheck
 staticcheck: ## Verifies `staticcheck` passes.
 	@echo "+ $@"
-	@staticcheck $(shell $(GO) list ./... | grep -v vendor) | grep -v '.pb.go:' | tee /dev/stderr
+	@if [[ ! -z "$(shell staticcheck $(shell $(GO) list ./... | grep -v vendor) | grep -v 'bindata.go:' | tee /dev/stderr)" ]]; then \
+		exit 1; \
+	fi
 
 .PHONY: cover
 cover: prebuild ## Runs go test with coverage.
diff --git a/examples/cl-k8s/main.go b/examples/cl-k8s/main.go
index 3d89c65..a02ff15 100644
--- a/examples/cl-k8s/main.go
+++ b/examples/cl-k8s/main.go
@@ -24,9 +24,8 @@ var (
 	containerID string
 	root        string
 
-	file      string
-	dir       string
-	shortpath string
+	file string
+	dir  string
 )
 
 func init() {