diff --git a/go/buildutil/go16_test.go b/go/buildutil/go16_test.go
deleted file mode 100644
index 7bb889eda8..0000000000
--- a/go/buildutil/go16_test.go
+++ /dev/null
@@ -1,14 +0,0 @@
-// Copyright 2014 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Incomplete source tree on Android.
-
-// +build !android
-// +build go1.6
-
-package buildutil_test
-
-func init() {
-	go16 = true
-}
diff --git a/go/buildutil/util_test.go b/go/buildutil/util_test.go
index 295e2918c4..dd55533ce6 100644
--- a/go/buildutil/util_test.go
+++ b/go/buildutil/util_test.go
@@ -18,8 +18,6 @@ import (
 	"golang.org/x/tools/go/buildutil"
 )
 
-var go16 bool // Go version >= go1.6
-
 func TestContainingPackage(t *testing.T) {
 	// unvirtualized:
 	goroot := runtime.GOROOT()
@@ -32,13 +30,6 @@ func TestContainingPackage(t *testing.T) {
 		{gopath + "/src/golang.org/x/tools/go/buildutil/util_test.go",
 			"golang.org/x/tools/go/buildutil"},
 	}
-	// TODO(adonovan): simplify after Go 1.6.
-	if go16 {
-		tests = append(tests, [2]string{
-			gopath + "/src/vendor/golang.org/x/net/http2/hpack/hpack.go",
-			"vendor/golang.org/x/net/http2/hpack",
-		})
-	}
 	for _, test := range tests {
 		file, want := test[0], test[1]
 		bp, err := buildutil.ContainingPackage(&build.Default, ".", file)
diff --git a/refactor/importgraph/go16_test.go b/refactor/importgraph/go16_test.go
deleted file mode 100644
index 4c0c693909..0000000000
--- a/refactor/importgraph/go16_test.go
+++ /dev/null
@@ -1,12 +0,0 @@
-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// +build !android
-// +build go1.6
-
-package importgraph_test
-
-func init() {
-	go16 = true
-}
diff --git a/refactor/importgraph/graph_test.go b/refactor/importgraph/graph_test.go
index 21c845d34f..52dd769590 100644
--- a/refactor/importgraph/graph_test.go
+++ b/refactor/importgraph/graph_test.go
@@ -9,10 +9,8 @@
 package importgraph_test
 
 import (
-	"fmt"
 	"go/build"
 	"sort"
-	"strings"
 	"testing"
 
 	"golang.org/x/tools/refactor/importgraph"
@@ -22,8 +20,6 @@ import (
 
 const this = "golang.org/x/tools/refactor/importgraph"
 
-var go16 bool // Go version >= go1.6
-
 func TestBuild(t *testing.T) {
 	forward, reverse, errors := importgraph.Build(&build.Default)
 
@@ -49,14 +45,6 @@ func TestBuild(t *testing.T) {
 		}
 	}
 
-	// Test vendor packages appear under their absolute names.
-	if go16 { // hack: Go 1.6+ only
-		if !forward["net/http"]["vendor/golang.org/x/net/http2/hpack"] {
-			t.Errorf("forward[net/http] does not include vendor/golang.org/x/net/http2/hpack: %v",
-				strings.Replace(fmt.Sprint(forward["net/http"]), ":true", "", -1))
-		}
-	}
-
 	// Test Search is reflexive.
 	if !forward.Search(this)[this] {
 		t.Errorf("irreflexive: forward.Search(importgraph)[importgraph] not found")