diff --git a/src/cmd/dist/test.go b/src/cmd/dist/test.go
index bd02149c115..554adea1b17 100644
--- a/src/cmd/dist/test.go
+++ b/src/cmd/dist/test.go
@@ -405,6 +405,9 @@ func (opts *goTest) buildArgs(t *tester) (build, run, pkgs, testFlags []string,
 	if opts.timeout != 0 {
 		d := opts.timeout * time.Duration(t.timeoutScale)
 		run = append(run, "-timeout="+d.String())
+	} else if t.timeoutScale != 1 {
+		const goTestDefaultTimeout = 10 * time.Minute // Default value of go test -timeout flag.
+		run = append(run, "-timeout="+(goTestDefaultTimeout*time.Duration(t.timeoutScale)).String())
 	}
 	if opts.short || t.short {
 		run = append(run, "-short")
diff --git a/src/cmd/go/internal/test/testflag.go b/src/cmd/go/internal/test/testflag.go
index 970c2f59e9a..425378889d9 100644
--- a/src/cmd/go/internal/test/testflag.go
+++ b/src/cmd/go/internal/test/testflag.go
@@ -61,7 +61,7 @@ func init() {
 	cf.String("run", "", "")
 	cf.Bool("short", false, "")
 	cf.String("skip", "", "")
-	cf.DurationVar(&testTimeout, "timeout", 10*time.Minute, "")
+	cf.DurationVar(&testTimeout, "timeout", 10*time.Minute, "") // known to cmd/dist
 	cf.String("fuzztime", "", "")
 	cf.String("fuzzminimizetime", "", "")
 	cf.StringVar(&testTrace, "trace", "", "")