diff --git a/src/elements/pump.c b/src/elements/pump.c
index 26b376cf0..77369c278 100644
--- a/src/elements/pump.c
+++ b/src/elements/pump.c
@@ -26,16 +26,13 @@ int update_PUMP(UPDATE_FUNC_ARGS) {
 		if (parts[i].temp<= -256.0+273.15)
 			parts[i].temp = -256.0+273.15;
 
-		if (pv[y/CELL][x/CELL]<(parts[i].temp-273.15))
-			pv[y/CELL][x/CELL] += 0.1f*((parts[i].temp-273.15)-pv[y/CELL][x/CELL]);
-		if (y+CELL<YRES && pv[y/CELL+1][x/CELL]<(parts[i].temp-273.15))
-			pv[y/CELL+1][x/CELL] += 0.1f*((parts[i].temp-273.15)-pv[y/CELL+1][x/CELL]);
-		if (x+CELL<XRES)
-		{
-			pv[y/CELL][x/CELL+1] += 0.1f*((parts[i].temp-273.15)-pv[y/CELL][x/CELL+1]);
-			if (y+CELL<YRES)
-				pv[y/CELL+1][x/CELL+1] += 0.1f*((parts[i].temp-273.15)-pv[y/CELL+1][x/CELL+1]);
-		}
+		for (rx=-1; rx<2; rx++)
+			for (ry=-1; ry<2; ry++)
+				if ((x+rx)-CELL>=0 && (y+ry)-CELL>0 && (x+rx)+CELL<XRES && (y+ry)+CELL<YRES && !(rx && ry))
+				{
+					pv[(y/CELL)+ry][(x/CELL)+rx] += 0.1f*((parts[i].temp-273.15)-pv[(y/CELL)+ry][(x/CELL)+rx]);
+				}
+		
 		for (rx=-2; rx<3; rx++)
 			for (ry=-2; ry<3; ry++)
 				if (x+rx>=0 && y+ry>0 && x+rx<XRES && y+ry<YRES && (rx || ry))