diff --git a/rtengine/cfa_linedn_RT.cc b/rtengine/cfa_linedn_RT.cc
index 0c38f01a3..982e68324 100644
--- a/rtengine/cfa_linedn_RT.cc
+++ b/rtengine/cfa_linedn_RT.cc
@@ -64,7 +64,9 @@ void RawImageSource::CLASS cfa_linedn(float noise)
 	int ex, ey; 
 	int verbose=1;
 	
-	float eps=1e-10;			//tolerance to avoid dividing by zero
+	const float clip_pt = 0.8*ri->defgain; 
+	
+	float eps=1e-5;			//tolerance to avoid dividing by zero
 	
 	float gauss[5] = {0.20416368871516755, 0.18017382291138087, 0.1238315368057753, 0.0662822452863612, 0.02763055063889883};
 	float rolloff[8] = {0, 0.135335, 0.249352, 0.411112, 0.606531, 0.800737, 0.945959, 1}; //gaussian with sigma=3
@@ -189,7 +191,8 @@ void RawImageSource::CLASS cfa_linedn(float noise)
 			for (rr=16; rr < numrows-16; rr++) {
 				row = rr + top; 
 				for (col=16+left, indx=rr*TS+16; indx < rr*TS+numcols-16; indx++, col++) {
-					ri->data[row][col] = CLIP((int)(cfadn[indx]+ 0.5)); 
+					if (ri->data[row][col]<clip_pt && cfadn[indx]<clip_pt) 
+						ri->data[row][col] = CLIP((int)(cfadn[indx]+ 0.5)); 
 				}
 			}
 			if(plistener) plistener->setProgress(fabs((float)top/height));