diff --git a/src/testing/sub_test.go b/src/testing/sub_test.go
index 5b226f85ad..6c7d83aac2 100644
--- a/src/testing/sub_test.go
+++ b/src/testing/sub_test.go
@@ -822,7 +822,7 @@ func TestLogAfterComplete(t *T) {
 						c2 <- fmt.Sprintf("subtest panic with unexpected value %v", p)
 						return
 					}
-					const want = "Log in goroutine after TestLateLog has completed"
+					const want = "Log in goroutine after TestLateLog has completed: log after test"
 					if !strings.Contains(s, want) {
 						c2 <- fmt.Sprintf("subtest panic %q does not contain %q", s, want)
 					}
diff --git a/src/testing/testing.go b/src/testing/testing.go
index 80354d5ce8..466dd96981 100644
--- a/src/testing/testing.go
+++ b/src/testing/testing.go
@@ -762,7 +762,7 @@ func (c *common) logDepth(s string, depth int) {
 				return
 			}
 		}
-		panic("Log in goroutine after " + c.name + " has completed")
+		panic("Log in goroutine after " + c.name + " has completed: " + s)
 	} else {
 		if c.chatty != nil {
 			if c.bench {