diff --git a/src/runtime/proc_test.go b/src/runtime/proc_test.go
index e7c0f3333ee..90a6cab874d 100644
--- a/src/runtime/proc_test.go
+++ b/src/runtime/proc_test.go
@@ -428,10 +428,13 @@ func TestPingPongHog(t *testing.T) {
 	<-lightChan
 
 	// Check that hogCount and lightCount are within a factor of
-	// 2, which indicates that both pairs of goroutines handed off
-	// the P within a time-slice to their buddy.
-	if hogCount > lightCount*2 || lightCount > hogCount*2 {
-		t.Fatalf("want hogCount/lightCount in [0.5, 2]; got %d/%d = %g", hogCount, lightCount, float64(hogCount)/float64(lightCount))
+	// 5, which indicates that both pairs of goroutines handed off
+	// the P within a time-slice to their buddy. We can use a
+	// fairly large factor here to make this robust: if the
+	// scheduler isn't working right, the gap should be ~1000X.
+	const factor = 5
+	if hogCount > lightCount*factor || lightCount > hogCount*factor {
+		t.Fatalf("want hogCount/lightCount in [%v, %v]; got %d/%d = %g", 1.0/factor, factor, hogCount, lightCount, float64(hogCount)/float64(lightCount))
 	}
 }