diff --git a/libs/freetdm/src/ftdm_io.c b/libs/freetdm/src/ftdm_io.c
index f97029b8dc..430b58a31e 100644
--- a/libs/freetdm/src/ftdm_io.c
+++ b/libs/freetdm/src/ftdm_io.c
@@ -2923,23 +2923,27 @@ FT_DECLARE(ftdm_status_t) ftdm_channel_command(ftdm_channel_t *ftdmchan, ftdm_co
 	case FTDM_COMMAND_ENABLE_DTMF_DETECT:
 		{
 			/* if they don't have thier own, use ours */
-			if (!ftdm_channel_test_feature(ftdmchan, FTDM_CHANNEL_FEATURE_DTMF_DETECT)) {
-				teletone_dtmf_detect_init (&ftdmchan->dtmf_detect, ftdmchan->rate);
-				ftdm_set_flag(ftdmchan, FTDM_CHANNEL_DTMF_DETECT);
-				ftdm_set_flag(ftdmchan, FTDM_CHANNEL_SUPRESS_DTMF);
-				ftdm_log_chan_msg(ftdmchan, FTDM_LOG_DEBUG, "Enabled software DTMF detector\n");
-				GOTO_STATUS(done, FTDM_SUCCESS);
+			if (FTDM_IS_VOICE_CHANNEL(ftdmchan)) {
+				if (!ftdm_channel_test_feature(ftdmchan, FTDM_CHANNEL_FEATURE_DTMF_DETECT)) {
+					teletone_dtmf_detect_init (&ftdmchan->dtmf_detect, ftdmchan->rate);
+					ftdm_set_flag(ftdmchan, FTDM_CHANNEL_DTMF_DETECT);
+					ftdm_set_flag(ftdmchan, FTDM_CHANNEL_SUPRESS_DTMF);
+					ftdm_log_chan_msg(ftdmchan, FTDM_LOG_DEBUG, "Enabled software DTMF detector\n");
+					GOTO_STATUS(done, FTDM_SUCCESS);
+				}
 			}
 		}
 		break;
 	case FTDM_COMMAND_DISABLE_DTMF_DETECT:
 		{
-			if (!ftdm_channel_test_feature(ftdmchan, FTDM_CHANNEL_FEATURE_DTMF_DETECT)) {
-                    		teletone_dtmf_detect_init (&ftdmchan->dtmf_detect, ftdmchan->rate);
-                    		ftdm_clear_flag(ftdmchan, FTDM_CHANNEL_DTMF_DETECT);
-				ftdm_clear_flag(ftdmchan, FTDM_CHANNEL_SUPRESS_DTMF);
-				ftdm_log_chan_msg(ftdmchan, FTDM_LOG_DEBUG, "Disabled software DTMF detector\n");
-				GOTO_STATUS(done, FTDM_SUCCESS);
+			if (FTDM_IS_VOICE_CHANNEL(ftdmchan)) {
+				if (!ftdm_channel_test_feature(ftdmchan, FTDM_CHANNEL_FEATURE_DTMF_DETECT)) {
+								teletone_dtmf_detect_init (&ftdmchan->dtmf_detect, ftdmchan->rate);
+								ftdm_clear_flag(ftdmchan, FTDM_CHANNEL_DTMF_DETECT);
+					ftdm_clear_flag(ftdmchan, FTDM_CHANNEL_SUPRESS_DTMF);
+					ftdm_log_chan_msg(ftdmchan, FTDM_LOG_DEBUG, "Disabled software DTMF detector\n");
+					GOTO_STATUS(done, FTDM_SUCCESS);
+				}
 			}
 		}
 		break;