diff --git a/build/ci.go b/build/ci.go
index d4e2814ec8..002f6bb152 100644
--- a/build/ci.go
+++ b/build/ci.go
@@ -214,7 +214,6 @@ func doInstall(cmdline []string) {
 	if flag.NArg() > 0 {
 		packages = flag.Args()
 	}
-	packages = build.ExpandPackagesNoVendor(packages)
 
 	if *arch == "" || *arch == runtime.GOARCH {
 		goinstall := goTool("install", buildFlags(env)...)
@@ -311,7 +310,6 @@ func doTest(cmdline []string) {
 	if len(flag.CommandLine.Args()) > 0 {
 		packages = flag.CommandLine.Args()
 	}
-	packages = build.ExpandPackagesNoVendor(packages)
 
 	// Run the actual tests.
 	// Test a single package at a time. CI builders are slow
diff --git a/internal/build/util.go b/internal/build/util.go
index 971d948c44..a1f4567776 100644
--- a/internal/build/util.go
+++ b/internal/build/util.go
@@ -153,32 +153,6 @@ func GoTool(tool string, args ...string) *exec.Cmd {
 	return exec.Command(filepath.Join(runtime.GOROOT(), "bin", "go"), args...)
 }
 
-// ExpandPackagesNoVendor expands a cmd/go import path pattern, skipping
-// vendored packages.
-func ExpandPackagesNoVendor(patterns []string) []string {
-	expand := false
-	for _, pkg := range patterns {
-		if strings.Contains(pkg, "...") {
-			expand = true
-		}
-	}
-	if expand {
-		cmd := GoTool("list", patterns...)
-		out, err := cmd.CombinedOutput()
-		if err != nil {
-			log.Fatalf("package listing failed: %v\n%s", err, string(out))
-		}
-		var packages []string
-		for _, line := range strings.Split(string(out), "\n") {
-			if !strings.Contains(line, "/vendor/") {
-				packages = append(packages, strings.TrimSpace(line))
-			}
-		}
-		return packages
-	}
-	return patterns
-}
-
 // UploadSFTP uploads files to a remote host using the sftp command line tool.
 // The destination host may be specified either as [user@]host[: or as a URI in
 // the form sftp://[user@]host[:port].