diff --git a/src/gui/render_simple.h b/src/gui/render_simple.h
index fc689a3c..322a1b37 100644
--- a/src/gui/render_simple.h
+++ b/src/gui/render_simple.h
@@ -77,6 +77,9 @@ static void conc4d(SCALERNAME,SBPP,DBPP,R)(const void *s) {
 #if (SCALERHEIGHT > 3) 
 			PTYPE *line3 = WC[2];
 #endif
+#if (SCALERHEIGHT > 4) 
+			PTYPE *line4 = WC[3];
+#endif
 #else
 #if (SCALERHEIGHT > 1) 
 		PTYPE *line1 = (PTYPE *)(((Bit8u*)line0)+ render.scale.outPitch);
@@ -87,6 +90,9 @@ static void conc4d(SCALERNAME,SBPP,DBPP,R)(const void *s) {
 #if (SCALERHEIGHT > 3) 
 		PTYPE *line3 = (PTYPE *)(((Bit8u*)line0)+ render.scale.outPitch * 3);
 #endif
+#if (SCALERHEIGHT > 4) 
+		PTYPE *line4 = (PTYPE *)(((Bit8u*)line0)+ render.scale.outPitch * 4);
+#endif
 #endif //defined(SCALERLINEAR)
 			hadChange = 1;
 			for (Bitu i = x > 32 ? 32 : x;i>0;i--,x--) {
@@ -104,6 +110,9 @@ static void conc4d(SCALERNAME,SBPP,DBPP,R)(const void *s) {
 #endif
 #if (SCALERHEIGHT > 3) 
 				line3 += SCALERWIDTH;
+#endif
+#if (SCALERHEIGHT > 4) 
+				line4 += SCALERWIDTH;
 #endif
 			}
 #if defined(SCALERLINEAR)
@@ -117,6 +126,10 @@ static void conc4d(SCALERNAME,SBPP,DBPP,R)(const void *s) {
 #if (SCALERHEIGHT > 3) 
 			BituMove(((Bit8u*)line0)-copyLen+render.scale.outPitch*3,WC[2], copyLen );
 #endif
+#if (SCALERHEIGHT > 4) 
+			BituMove(((Bit8u*)line0)-copyLen+render.scale.outPitch*4,WC[3], copyLen );
+#endif
+
 #endif //defined(SCALERLINEAR)
 		}
 	}