diff --git a/src/helper/bit-tools/rect-tool.js b/src/helper/bit-tools/rect-tool.js
index cbaef41b..d5de5ebe 100644
--- a/src/helper/bit-tools/rect-tool.js
+++ b/src/helper/bit-tools/rect-tool.js
@@ -1,6 +1,6 @@
 import paper from '@scratch/paper';
 import Modes from '../../lib/modes';
-import {drawRect} from '../bitmap';
+import {fillRect} from '../bitmap';
 import {createCanvas, getRaster} from '../layer';
 import {clearSelection} from '../selection';
 import BoundingBoxTool from '../selection-tools/bounding-box-tool';
@@ -25,7 +25,7 @@ class RectTool extends paper.Tool {
         this.onUpdateImage = onUpdateImage;
         this.boundingBoxTool = new BoundingBoxTool(Modes.BIT_RECT, setSelectedItems, clearSelectedItems, onUpdateImage);
         const nudgeTool = new NudgeTool(this.boundingBoxTool, onUpdateImage);
-        
+
         // We have to set these functions instead of just declaring them because
         // paper.js tools hook up the listeners in the setter functions.
         this.onMouseDown = this.handleMouseDown;
@@ -98,7 +98,7 @@ class RectTool extends paper.Tool {
         if (this.rect) this.rect.remove();
         this.rect = new paper.Shape.Rectangle(baseRect);
         this.rect.fillColor = this.color;
-        
+
         if (event.modifiers.alt) {
             this.rect.position = event.downPoint;
         } else {
@@ -107,7 +107,7 @@ class RectTool extends paper.Tool {
     }
     handleMouseUp (event) {
         if (event.event.button > 0 || !this.active) return; // only first mouse button
-        
+
         if (this.isBoundingBoxMode) {
             this.boundingBoxTool.onMouseUp(event);
             this.isBoundingBoxMode = null;
@@ -134,7 +134,7 @@ class RectTool extends paper.Tool {
         const tmpCanvas = createCanvas();
         const context = tmpCanvas.getContext('2d');
         context.fillStyle = this.color;
-        drawRect(this.rect, context);
+        fillRect(this.rect, context);
         getRaster().drawImage(tmpCanvas, new paper.Point());
 
         this.rect.remove();
diff --git a/src/helper/bitmap.js b/src/helper/bitmap.js
index 6af4d380..22ef902b 100644
--- a/src/helper/bitmap.js
+++ b/src/helper/bitmap.js
@@ -523,7 +523,7 @@ const floodFillAll = function (x, y, color, context) {
  * @param {!paper.Shape.Rectangle} rect The rectangle to draw to the canvas
  * @param {!HTMLCanvas2DContext} context The context in which to draw
  */
-const drawRect = function (rect, context) {
+const fillRect = function (rect, context) {
     // No rotation component to matrix
     if (rect.matrix.b === 0 && rect.matrix.c === 0) {
         const width = rect.size.width * rect.matrix.a;
@@ -541,25 +541,27 @@ const drawRect = function (rect, context) {
     const heightPoint = rect.matrix.transform(new paper.Point(-rect.size.width / 2, rect.size.height / 2));
     const endPoint = rect.matrix.transform(new paper.Point(rect.size.width / 2, rect.size.height / 2));
     const center = rect.matrix.transform(new paper.Point());
-    forEachLinePoint(startPoint, widthPoint, (x, y) => {
-        context.fillRect(x, y, 1, 1);
-    });
-    forEachLinePoint(startPoint, heightPoint, (x, y) => {
-        context.fillRect(x, y, 1, 1);
-    });
-    forEachLinePoint(endPoint, widthPoint, (x, y) => {
-        context.fillRect(x, y, 1, 1);
-    });
-    forEachLinePoint(endPoint, heightPoint, (x, y) => {
-        context.fillRect(x, y, 1, 1);
-    });
-    floodFill(~~center.x, ~~center.y, context.fillStyle, context);
+    const points = [startPoint, widthPoint, heightPoint, endPoint].sort((a, b) => a.x - b.x);
+
+    const solveY = (point1, point2, x) => {
+        if (point2.x === point1.x) return center.x > point1.x ? Number.NEGATIVE_INFINITY : Number.POSITIVE_INFINITY;
+        return ((point2.y - point1.y) / (point2.x - point1.x) * (x - point1.x)) + point1.y;
+    };
+    for (let x = Math.round(points[0].x); x < Math.round(points[3].x); x++) {
+        const ys = [
+            solveY(startPoint, widthPoint, x + .5),
+            solveY(startPoint, heightPoint, x + .5),
+            solveY(endPoint, widthPoint, x + .5),
+            solveY(endPoint, heightPoint, x + .5)
+        ].sort((a, b) => a - b);
+        context.fillRect(x, Math.round(ys[1]), 1, Math.max(1, Math.round(ys[2]) - Math.round(ys[1])));
+    }
 };
 
 export {
     convertToBitmap,
     convertToVector,
-    drawRect,
+    fillRect,
     floodFill,
     floodFillAll,
     getBrushMark,