diff --git a/server.go b/server.go
index 1c42b6eff..d71c094e2 100644
--- a/server.go
+++ b/server.go
@@ -279,7 +279,7 @@ func (s *Server) serveNewHTTP2Transport(c net.Conn, authInfo credentials.AuthInf
 		return
 	}
 	if !s.addConn(st) {
-		c.Close()
+		st.Close()
 		return
 	}
 	s.serveStreams(st)
diff --git a/test/end2end_test.go b/test/end2end_test.go
index f1c7b426a..9461cd6ee 100644
--- a/test/end2end_test.go
+++ b/test/end2end_test.go
@@ -1354,7 +1354,7 @@ func interestingGoroutines() (gs []string) {
 	return
 }
 
-var failOnLeaks = flag.Bool("fail_on_leaks", false, "Fail tests if goroutines leak.")
+var failOnLeaks = flag.Bool("fail_on_leaks", true, "Fail tests if goroutines leak.")
 
 // leakCheck snapshots the currently-running goroutines and returns a
 // function to be run at the end of tests to see whether any