diff --git a/rtengine/procevents.h b/rtengine/procevents.h
index 0c2050576..a67680382 100644
--- a/rtengine/procevents.h
+++ b/rtengine/procevents.h
@@ -188,7 +188,7 @@ enum ProcEvent {
 	EvRGBgCurve=163,
 	EvRGBbCurve=164,
 	EvNeutralExp=165,
-//	EvLBWtoning=166,  -- can be reused --
+        EvDemosaicMethodPreProc=166,
 	EvLCCCurve=167,
 	EvLCHCurve=168,
 	EvVibranceSkinTonesCurve=169,
diff --git a/rtengine/refreshmap.cc b/rtengine/refreshmap.cc
index 90e37ceab..73f0007da 100644
--- a/rtengine/refreshmap.cc
+++ b/rtengine/refreshmap.cc
@@ -186,7 +186,7 @@ RGBCURVE,         // EvRGBrCurve
 RGBCURVE,         // EvRGBgCurve
 RGBCURVE,         // EvRGBbCurve
 RGBCURVE,         // EvNeutralExp
-NONE,             // --unused--,
+DEMOSAIC|M_PREPROC, // EvDemosaicMethodPreProc
 LUMINANCECURVE,   // EvLCCurve
 LUMINANCECURVE,   // EvLCHCurve
 RGBCURVE,         // EvVibranceSkinTonesCurve
diff --git a/rtgui/rawprocess.cc b/rtgui/rawprocess.cc
index 4a3c0dca1..0522f8e24 100644
--- a/rtgui/rawprocess.cc
+++ b/rtgui/rawprocess.cc
@@ -91,6 +91,7 @@ void RawProcess::read(const rtengine::procparams::ProcParams* pp, const ParamsEd
    for( size_t i=0; i< procparams::RAWParams::numMethods;i++)
        if( pp->raw.dmethod == procparams::RAWParams::methodstring[i]){
            dmethod->set_active(i);
+	   oldSelection = i;
            break;
        }
 
@@ -221,11 +222,17 @@ void RawProcess::methodChanged ()
 	}
 	
 	Glib::ustring methodName="";
-	if( curSelection>=0 && curSelection < procparams::RAWParams::numMethods)
+	bool ppreq = false;
+	if( curSelection>=0 && curSelection < procparams::RAWParams::numMethods) {
 	    methodName = procparams::RAWParams::methodstring[curSelection];
+	    if (curSelection == procparams::RAWParams::mono || oldSelection == procparams::RAWParams::mono) {
+		    ppreq = true;
+	    }
+	}
+	oldSelection = curSelection;
 
     if (listener)
-        listener->panelChanged (EvDemosaicMethod, methodName);
+	    listener->panelChanged (ppreq ? EvDemosaicMethodPreProc : EvDemosaicMethod, methodName);
 }
 
 void RawProcess::dcbEnhanceChanged ()
diff --git a/rtgui/rawprocess.h b/rtgui/rawprocess.h
index 5fbee271d..f88c7bdc0 100644
--- a/rtgui/rawprocess.h
+++ b/rtgui/rawprocess.h
@@ -41,6 +41,7 @@ class RawProcess : public ToolParamBlock, public AdjusterListener, public Foldab
     Adjuster* lmmseIterations;
 
     bool lastDCBen;
+    int oldSelection;
 	//bool lastALLen;
     sigc::connection methodconn,dcbEnhconn;  //,allEnhconn;
   public: