diff --git a/http2/transport.go b/http2/transport.go
index e6b321f..da91d19 100644
--- a/http2/transport.go
+++ b/http2/transport.go
@@ -951,6 +951,9 @@
 	for {
 		cc.lastActive = time.Now()
 		if cc.closed || !cc.canTakeNewRequestLocked() {
+			if waitingForConn != nil {
+				close(waitingForConn)
+			}
 			return errClientConnUnusable
 		}
 		if int64(len(cc.streams))+1 <= int64(cc.maxConcurrentStreams) {