diff --git a/src/cmd/go/internal/generate/generate.go b/src/cmd/go/internal/generate/generate.go
index 198ca1c..315db69 100644
--- a/src/cmd/go/internal/generate/generate.go
+++ b/src/cmd/go/internal/generate/generate.go
@@ -22,6 +22,7 @@
 	"cmd/go/internal/cfg"
 	"cmd/go/internal/load"
 	"cmd/go/internal/modload"
+	"cmd/go/internal/str"
 	"cmd/go/internal/work"
 )
 
@@ -438,7 +439,7 @@
 	cmd.Stderr = os.Stderr
 	// Run the command in the package directory.
 	cmd.Dir = g.dir
-	cmd.Env = append(cfg.OrigEnv, g.env...)
+	cmd.Env = str.StringList(cfg.OrigEnv, g.env)
 	err := cmd.Run()
 	if err != nil {
 		g.errorf("running %q: %s", words[0], err)
diff --git a/src/cmd/go/internal/test/test.go b/src/cmd/go/internal/test/test.go
index dbb8992..ec7bde1 100644
--- a/src/cmd/go/internal/test/test.go
+++ b/src/cmd/go/internal/test/test.go
@@ -1157,7 +1157,7 @@
 
 	cmd := exec.Command(args[0], args[1:]...)
 	cmd.Dir = a.Package.Dir
-	cmd.Env = base.EnvForDir(cmd.Dir, cfg.OrigEnv)
+	cmd.Env = base.EnvForDir(cmd.Dir, cfg.OrigEnv[:len(cfg.OrigEnv):len(cfg.OrigEnv)])
 	cmd.Stdout = stdout
 	cmd.Stderr = stdout