diff --git a/src/rhd_dig.c b/src/rhd_dig.c
index c2ed8fe..a81954c 100644
--- a/src/rhd_dig.c
+++ b/src/rhd_dig.c
@@ -277,6 +277,7 @@ TMDSTransmitterPropertyControl(struct rhdOutput *Output,
 	    switch (Property) {
 		case RHD_OUTPUT_COHERENT:
 		case RHD_OUTPUT_HDMI:
+if (Private->Mode == NULL) xf86DrvMsg(Output->scrnIndex, X_ERROR, "%s: no ->Mode (it's NULL)\n", __func__);
 		    Output->Mode(Output, Private->Mode);
 		    Output->Power(Output, RHD_POWER_ON);
 		    break;
@@ -838,6 +839,7 @@ ATOMTransmitterSet(struct rhdOutput *Output, struct rhdCrtc *Crtc, DisplayModePt
     RHDFUNC(Output);
 
     atc->Coherent = Private->Coherent;
+if (Mode == NULL) xf86DrvMsg(rhdPtr->scrnIndex, X_ERROR, "%s: I need Mode->SynthClock, but Mode is NULL!\n", __func__);
     atc->PixelClock = Mode->SynthClock;
 
     rhdPrintDigDebug(rhdPtr,__func__);