diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index 35316ce247..8f44194ba4 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -7199,7 +7199,8 @@ static int sip_indicate(struct ast_channel *ast, int condition, const void *data
 		break;
 	case AST_CONTROL_UPDATE_RTP_PEER: /* Absorb this since it is handled by the bridge */
 		break;
-	case AST_CONTROL_FLASH: /* Absorb this since it is irrelevant to SIP. */
+	case AST_CONTROL_FLASH: /* We don't currently handle AST_CONTROL_FLASH here, but it is expected, so we don't need to warn either. */
+		res = -1;
 		break;
 	case AST_CONTROL_PVT_CAUSE_CODE: /* these should be handled by the code in channel.c */
 	case -1: