diff --git a/dsp.c b/dsp.c
index d4359c7902..5bf9d31f73 100755
--- a/dsp.c
+++ b/dsp.c
@@ -1205,6 +1205,7 @@ struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp,
 		return &dsp->f;
 	}
 	if ((dsp->features & DSP_FEATURE_BUSY_DETECT) && ast_dsp_busydetect(dsp)) {
+		chan->_softhangup |= AST_SOFTHANGUP_DEV;
 		memset(&dsp->f, 0, sizeof(dsp->f));
 		dsp->f.frametype = AST_FRAME_CONTROL;
 		dsp->f.subclass = AST_CONTROL_BUSY;