diff --git a/src/pkg/testing/testing.go b/src/pkg/testing/testing.go
index 357d6f5f273..b1dafd0c3d5 100644
--- a/src/pkg/testing/testing.go
+++ b/src/pkg/testing/testing.go
@@ -166,21 +166,17 @@ func decorate(s string) string {
 		line = 1
 	}
 	buf := new(bytes.Buffer)
+	// Every line is indented at least one tab.
+	buf.WriteByte('\t')
 	fmt.Fprintf(buf, "%s:%d: ", file, line)
-
 	lines := strings.Split(s, "\n")
 	if l := len(lines); l > 1 && lines[l-1] == "" {
 		lines = lines[:l-1]
 	}
 	for i, line := range lines {
-		if i > 0 {
-			buf.WriteByte('\n')
-		}
-		// Every line is indented at least one tab.
-		buf.WriteByte('\t')
 		if i > 0 {
 			// Second and subsequent lines are indented an extra tab.
-			buf.WriteByte('\t')
+			buf.WriteString("\n\t\t")
 		}
 		buf.WriteString(line)
 	}