diff --git a/src/crypto/tls/common.go b/src/crypto/tls/common.go
index 5fd92d3c639..67385f1fef2 100644
--- a/src/crypto/tls/common.go
+++ b/src/crypto/tls/common.go
@@ -962,6 +962,7 @@ func (c *Config) ticketKeys(configForClient *Config) []ticketKey {
 	if configForClient != nil {
 		configForClient.mutex.RLock()
 		if configForClient.SessionTicketsDisabled {
+			configForClient.mutex.RUnlock()
 			return nil
 		}
 		configForClient.initLegacySessionTicketKeyRLocked()