diff --git a/src/mod/codecs/mod_amr/mod_amr.c b/src/mod/codecs/mod_amr/mod_amr.c
index 56294e2a5e..1155a29a1c 100644
--- a/src/mod/codecs/mod_amr/mod_amr.c
+++ b/src/mod/codecs/mod_amr/mod_amr.c
@@ -246,7 +246,7 @@ static switch_status_t switch_amr_init(switch_codec_t *codec, switch_codec_flag_
 	switch_codec_fmtp_t codec_fmtp;
 	amr_codec_settings_t amr_codec_settings = { 0 };
 	int encoding, decoding;
-	int x, i, argc;
+	int x, i, argc, fmtptmp_pos;
 	char *argv[10];
 	char fmtptmp[128];
 
@@ -332,25 +332,38 @@ static switch_status_t switch_amr_init(switch_codec_t *codec, switch_codec_flag_
 
 		if (context->enc_modes) {
 			/* choose the highest mode (bitrate) for high audio quality */
-			for (i = 7; i > -1; i--) {
+			for (i = SWITCH_AMR_MODES-2; i > -1; i--) {
 				if (context->enc_modes & (1 << i)) {
 					context->enc_mode = (switch_byte_t) i;
 					break;
 				}
 			}
+
+			/* re-create mode-set */
+			fmtptmp_pos = switch_snprintf(fmtptmp, sizeof(fmtptmp), "mode-set=");
+			for (i = 0; SWITCH_AMR_MODES-1 > i; ++i) {
+				if (context->enc_modes & (1 << i)) {
+					fmtptmp_pos += switch_snprintf(fmtptmp + fmtptmp_pos, sizeof(fmtptmp) - fmtptmp_pos, fmtptmp_pos > strlen("mode-set=") ? ",%d" : "%d", i);
+				}
+			}
+
+		} else {
+			/* use default mode-set */
+			fmtptmp_pos = switch_snprintf(fmtptmp, sizeof(fmtptmp), "mode-set=%d", context->enc_mode);
 		}
 
 		if (globals.adjust_bitrate) {
 			switch_set_flag(codec, SWITCH_CODEC_FLAG_HAS_ADJ_BITRATE);
 		}
 
+
+
 		if (!globals.volte) {
-			switch_snprintf(fmtptmp, sizeof(fmtptmp), "octet-align=%d; mode-set=%d", switch_test_flag(context, AMR_OPT_OCTET_ALIGN) ? 1 : 0,
-							context->enc_mode);
+			fmtptmp_pos += switch_snprintf(fmtptmp + fmtptmp_pos, sizeof(fmtptmp) - fmtptmp_pos, ";octet-align=%d", switch_test_flag(context, AMR_OPT_OCTET_ALIGN) ? 1 : 0);
 		} else {
 			/* some UEs reject the call with 488 if mode-change-capability is not 2 */
-			switch_snprintf(fmtptmp, sizeof(fmtptmp), "octet-align=%d; mode-set=%d; max-red=0; mode-change-capability=2",
-							switch_test_flag(context, AMR_OPT_OCTET_ALIGN) ? 1 : 0, context->enc_mode);
+			fmtptmp_pos += switch_snprintf(fmtptmp + fmtptmp_pos, sizeof(fmtptmp) - fmtptmp_pos, ";octet-align=%d;max-red=0;mode-change-capability=2",
+							switch_test_flag(context, AMR_OPT_OCTET_ALIGN) ? 1 : 0);
 		}
 		codec->fmtp_out = switch_core_strdup(codec->memory_pool, fmtptmp);
 
diff --git a/src/mod/codecs/mod_amrwb/mod_amrwb.c b/src/mod/codecs/mod_amrwb/mod_amrwb.c
index b3690520d2..7fc44150d1 100644
--- a/src/mod/codecs/mod_amrwb/mod_amrwb.c
+++ b/src/mod/codecs/mod_amrwb/mod_amrwb.c
@@ -189,7 +189,7 @@ static switch_status_t switch_amrwb_init(switch_codec_t *codec, switch_codec_fla
 #else
 	struct amrwb_context *context = NULL;
 	int encoding, decoding;
-	int x, i, argc;
+	int x, i, argc, fmtptmp_pos;
 	char *argv[10];
 	char fmtptmp[128];
 
@@ -266,12 +266,24 @@ static switch_status_t switch_amrwb_init(switch_codec_t *codec, switch_codec_fla
 
 		if (context->enc_modes) {
 			/* choose the highest mode (bitrate) for high audio quality. */
-			for (i = 8; i > -1; i--) {
+			for (i = SWITCH_AMRWB_MODES-2; i > -1; i--) {
 				if (context->enc_modes & (1 << i)) {
 					context->enc_mode = (switch_byte_t) i;
 					break;
 				}
 			}
+
+			/* re-create mode-set */
+			fmtptmp_pos = switch_snprintf(fmtptmp, sizeof(fmtptmp), "mode-set=");
+			for (i = 0; SWITCH_AMRWB_MODES-1 > i; ++i) {
+				if (context->enc_modes & (1 << i)) {
+					fmtptmp_pos += switch_snprintf(fmtptmp + fmtptmp_pos, sizeof(fmtptmp) - fmtptmp_pos, fmtptmp_pos > strlen("mode-set=") ? ",%d" : "%d", i);
+				}
+			}
+
+		} else {
+			/* use default mode-set */
+			fmtptmp_pos = switch_snprintf(fmtptmp, sizeof(fmtptmp), "mode-set=%d", context->enc_mode);
 		}
 
 		if (globals.adjust_bitrate) {
@@ -279,11 +291,11 @@ static switch_status_t switch_amrwb_init(switch_codec_t *codec, switch_codec_fla
 		}
 
 		if (!globals.volte) {
-			switch_snprintf(fmtptmp, sizeof(fmtptmp), "octet-align=%d; mode-set=%d",
-					switch_test_flag(context, AMRWB_OPT_OCTET_ALIGN) ? 1 : 0, context->enc_mode);
+			fmtptmp_pos += switch_snprintf(fmtptmp + fmtptmp_pos, sizeof(fmtptmp) - fmtptmp_pos, ";octet-align=%d",
+					switch_test_flag(context, AMRWB_OPT_OCTET_ALIGN) ? 1 : 0);
 		} else {
-			switch_snprintf(fmtptmp, sizeof(fmtptmp), "octet-align=%d; mode-set=%d; max-red=0; mode-change-capability=2",
-					switch_test_flag(context, AMRWB_OPT_OCTET_ALIGN) ? 1 : 0, context->enc_mode);
+			fmtptmp_pos += switch_snprintf(fmtptmp + fmtptmp_pos, sizeof(fmtptmp) - fmtptmp_pos, ";octet-align=%d;max-red=0;mode-change-capability=2",
+					switch_test_flag(context, AMRWB_OPT_OCTET_ALIGN) ? 1 : 0);
 		}
 		codec->fmtp_out = switch_core_strdup(codec->memory_pool, fmtptmp);