diff --git a/channels/chan_zap.c b/channels/chan_zap.c
index c0af6cf35..818a07270 100755
--- a/channels/chan_zap.c
+++ b/channels/chan_zap.c
@@ -3673,6 +3673,11 @@ struct ast_frame  *zt_read(struct ast_channel *ast)
 					f = NULL;
 				}
 			} else if (f->frametype == AST_FRAME_DTMF) {
+				if (!p->proceeding && p->sig==SIG_PRI && p->pri && p->pri->overlapdial) {
+					/* Don't accept in-band DTMF when in overlap dial mode */
+					f->frametype = AST_FRAME_NULL;
+					f->subclass = 0;
+				}
 				/* DSP clears us of being pulse */
 				p->pulsedial = 0;
 			}