diff --git a/singleflight/singleflight.go b/singleflight/singleflight.go
index 690eb85..7c7fc50 100644
--- a/singleflight/singleflight.go
+++ b/singleflight/singleflight.go
@@ -52,10 +52,6 @@
 	val interface{}
 	err error
 
-	// forgotten indicates whether Forget was called with this call's key
-	// while the call was still in flight.
-	forgotten bool
-
 	// These fields are read and written with the singleflight
 	// mutex held before the WaitGroup is done, and are read but
 	// not written after the WaitGroup is done.
@@ -151,7 +147,7 @@
 		c.wg.Done()
 		g.mu.Lock()
 		defer g.mu.Unlock()
-		if !c.forgotten {
+		if g.m[key] == c {
 			delete(g.m, key)
 		}
 
@@ -204,9 +200,6 @@
 // an earlier call to complete.
 func (g *Group) Forget(key string) {
 	g.mu.Lock()
-	if c, ok := g.m[key]; ok {
-		c.forgotten = true
-	}
 	delete(g.m, key)
 	g.mu.Unlock()
 }