diff --git a/cmd/goimports/goimports.go b/cmd/goimports/goimports.go
index 0a9fe12a13..a476a7f3c3 100644
--- a/cmd/goimports/goimports.go
+++ b/cmd/goimports/goimports.go
@@ -10,6 +10,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"go/build"
 	"go/scanner"
 	"io"
 	"io/ioutil"
@@ -21,7 +22,7 @@ import (
 	"runtime/pprof"
 	"strings"
 
-	"golang.org/x/tools/imports"
+	"golang.org/x/tools/internal/imports"
 )
 
 var (
@@ -42,13 +43,18 @@ var (
 		TabIndent: true,
 		Comments:  true,
 		Fragment:  true,
+		// This environment, and its caches, will be reused for the whole run.
+		Env: &imports.ProcessEnv{
+			GOPATH: build.Default.GOPATH,
+			GOROOT: build.Default.GOROOT,
+		},
 	}
 	exitCode = 0
 )
 
 func init() {
 	flag.BoolVar(&options.AllErrors, "e", false, "report all errors (not just the first 10 on different lines)")
-	flag.StringVar(&imports.LocalPrefix, "local", "", "put imports beginning with this string after 3rd-party packages; comma-separated list")
+	flag.StringVar(&options.Env.LocalPrefix, "local", "", "put imports beginning with this string after 3rd-party packages; comma-separated list")
 	flag.BoolVar(&options.FormatOnly, "format-only", false, "if true, don't fix imports and only format. In this mode, goimports is effectively gofmt, with the addition that imports are grouped into sections.")
 }
 
@@ -252,7 +258,7 @@ func gofmtMain() {
 
 	if verbose {
 		log.SetFlags(log.LstdFlags | log.Lmicroseconds)
-		imports.Debug = true
+		options.Env.Debug = true
 	}
 	if options.TabWidth < 0 {
 		fmt.Fprintf(os.Stderr, "negative tabwidth %d\n", options.TabWidth)