Index: channels/chan_sip.c
===================================================================
--- channels/chan_sip.c	(revision 322174)
+++ channels/chan_sip.c	(working copy)
@@ -6284,12 +6284,20 @@
 	switch (frame->frametype) {
 	case AST_FRAME_VOICE:
 		if (!(frame->subclass.codec & ast->nativeformats)) {
+			struct ast_channel *bridge;
 			char s1[512], s2[512], s3[512];
 			ast_log(LOG_WARNING, "Asked to transmit frame type %s, while native formats is %s read/write = %s/%s\n",
 				ast_getformatname(frame->subclass.codec),
 				ast_getformatname_multiple(s1, sizeof(s1), ast->nativeformats & AST_FORMAT_AUDIO_MASK),
 				ast_getformatname_multiple(s2, sizeof(s2), ast->readformat),
 				ast_getformatname_multiple(s3, sizeof(s3), ast->writeformat));
+			bridge = ast_bridged_channel(ast);
+			if (bridge && !ast_channel_trylock(bridge)) {
+				ast_set_write_format(ast, frame->subclass.codec);
+				ast_log(LOG_WARNING, "Attempting to change formats making %s and %s compat.\n", ast->name, bridge->name);
+				ast_channel_make_compatible(ast, bridge);
+				ast_channel_unlock(bridge);
+			}
 			return 0;
 		}
 		if (p) {