diff --git a/.golangci.yml b/.golangci.yml
index fa4b1c0..2dbc993 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -1,6 +1,7 @@
 linters:
   enable-all: true
   disable:
+  - funlen
   - maligned
   - lll
   - gosec
diff --git a/go.mod b/go.mod
index 88c746a..013697f 100644
--- a/go.mod
+++ b/go.mod
@@ -1,9 +1,8 @@
 module github.com/mmcloughlin/avo
 
+go 1.11
+
 require (
-	github.com/campoy/embedmd v1.0.0 // indirect
-	github.com/dlespiau/covertool v0.0.0-20180314162135-b0c4c6d0583a // indirect
-	github.com/urfave/cli v1.20.0 // indirect
-	golang.org/x/arch v0.0.0-20181203225421-5a4828bb7045
-	golang.org/x/tools v0.0.0-20190106171756-3ef68632349c
+	golang.org/x/arch v0.0.0-20190909030613-46d78d1859ac
+	golang.org/x/tools v0.0.0-20190914235951-31e00f45c22e
 )
diff --git a/go.sum b/go.sum
index b355117..24920a3 100644
--- a/go.sum
+++ b/go.sum
@@ -1,12 +1,12 @@
-github.com/campoy/embedmd v1.0.0 h1:V4kI2qTJJLf4J29RzI/MAt2c3Bl4dQSYPuflzwFH2hY=
-github.com/campoy/embedmd v1.0.0/go.mod h1:oxyr9RCiSXg0M3VJ3ks0UGfp98BpSSGr0kpiX3MzVl8=
-github.com/dlespiau/covertool v0.0.0-20180314162135-b0c4c6d0583a h1:+cYgqwB++gEE09SluRYGqJyDhWmLmdWZ2cXlOXSGV8w=
-github.com/dlespiau/covertool v0.0.0-20180314162135-b0c4c6d0583a/go.mod h1:/eQMcW3eA1bzKx23ZYI2H3tXPdJB5JWYTHzoUPBvQY4=
-github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
-github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/urfave/cli v1.20.0 h1:fDqGv3UG/4jbVl/QkFwEdddtEDjh/5Ov6X+0B/3bPaw=
-github.com/urfave/cli v1.20.0/go.mod h1:70zkFmudgCuE/ngEzBv17Jvp/497gISqfk5gWijbERA=
-golang.org/x/arch v0.0.0-20181203225421-5a4828bb7045 h1:Pn8fQdvx+z1avAi7fdM2kRYWQNxGlavNDSyzrQg2SsU=
-golang.org/x/arch v0.0.0-20181203225421-5a4828bb7045/go.mod h1:cYlCBUl1MsqxdiKgmc4uh7TxZfWSFLOGSRR090WDxt8=
-golang.org/x/tools v0.0.0-20190106171756-3ef68632349c h1:mYpOyPbwiBWL7unJZKj7TctJ0vXSRdNUQBq8pGosFgI=
-golang.org/x/tools v0.0.0-20190106171756-3ef68632349c/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/arch v0.0.0-20190909030613-46d78d1859ac h1:YcaRWbSY2VfP0/k25uHKKrk3Vs3C7mo03vq103Ire8E=
+golang.org/x/arch v0.0.0-20190909030613-46d78d1859ac/go.mod h1:flIaEI6LNU6xOCD5PaJvn9wGP0agmIOqjrtsKGRguv4=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/tools v0.0.0-20190914235951-31e00f45c22e h1:nOOVVcLC+/3MeovP40q5lCiWmP1Z1DaN8yn8ngU63hw=
+golang.org/x/tools v0.0.0-20190914235951-31e00f45c22e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+rsc.io/pdf v0.1.1 h1:k1MczvYDUvJBe93bYd7wrZLLUEcLZAuF824/I4e5Xr4=
+rsc.io/pdf v0.1.1/go.mod h1:n8OzWcQ6Sp37PL01nO98y4iUCRdTGarVfzxY20ICaU4=
diff --git a/script/bootstrap b/script/bootstrap
index ba5973f..5b043c8 100755
--- a/script/bootstrap
+++ b/script/bootstrap
@@ -1,17 +1,18 @@
 #!/bin/bash -ex
 
-# Limit dependencies to golang.org/x repos
-go get -u \
-    golang.org/x/arch/x86/... \
-    golang.org/x/tools/go/...
+# Install dependencies.
+go mod download
 
 # Standalone version of the asmdecl analysis tool.
 go install ./internal/cmd/asmdecl
 
 # Install golangci-lint
-golangci_lint_version='v1.17.1'
+golangci_lint_version='v1.18.0'
 curl -sfL https://install.goreleaser.com/github.com/golangci/golangci-lint.sh | sh -s -- -b $GOPATH/bin ${golangci_lint_version}
 
+# Turn off modules for tools install.
+export GO111MODULE=off
+
 # embedmd required for documentation generation
 go get -u github.com/campoy/embedmd