diff --git a/src/gameobjects/shape/line/Line.js b/src/gameobjects/shape/line/Line.js
index f1931f90fa..44960b3b75 100644
--- a/src/gameobjects/shape/line/Line.js
+++ b/src/gameobjects/shape/line/Line.js
@@ -64,9 +64,6 @@ var Line = new Class({
 
         Shape.call(this, scene, 'Line', new GeomLine(x1, y1, x2, y2));
 
-        var width = Math.max(1, this.geom.right - this.geom.left);
-        var height = Math.max(1, this.geom.bottom - this.geom.top);
-
         /**
          * The width (or thickness) of the line.
          * See the setLineWidth method for extra details on changing this on WebGL.
@@ -98,7 +95,7 @@ var Line = new Class({
         this._endWidth = 1;
 
         this.setPosition(x, y);
-        this.setSize(width, height);
+        this.updateSize();
 
         if (strokeColor !== undefined)
         {
@@ -153,9 +150,29 @@ var Line = new Class({
     {
         this.geom.setTo(x1, y1, x2, y2);
 
+        this.updateSize();
+
         return this;
-    }
+    },
 
+    /**
+     * Updates the width and height of the Line based on its geometry.
+     *
+     * @method Phaser.GameObjects.Line#updateSize
+     * @private
+     * @since 4.1.0
+     *
+     * @return {this} This Line instance.
+     */
+    updateSize: function ()
+    {
+        var width = Math.max(1, this.geom.right - this.geom.left);
+        var height = Math.max(1, this.geom.bottom - this.geom.top);
+
+        this.setSize(width, height);
+
+        return this;
+    }
 });
 
 module.exports = Line;
diff --git a/tests/gameobjects/shape/line/Line.test.js b/tests/gameobjects/shape/line/Line.test.js
index 727b5bff8b..8cecb0b0c4 100644
--- a/tests/gameobjects/shape/line/Line.test.js
+++ b/tests/gameobjects/shape/line/Line.test.js
@@ -1,4 +1,5 @@
 var Line = require('../../../../src/gameobjects/shape/line/Line');
+var GeomLine = require('../../../../src/geom/line/Line');
 
 describe('Line', function ()
 {
@@ -88,11 +89,9 @@ describe('Line', function ()
 
         beforeEach(function ()
         {
-            geomSetTo = vi.fn();
             obj = Object.create(Line.prototype);
-            obj.geom = {
-                setTo: geomSetTo
-            };
+            obj.geom = new GeomLine();
+            geomSetTo = vi.spyOn(obj.geom, 'setTo');
         });
 
         it('should delegate to geom.setTo with the provided coordinates', function ()
@@ -136,5 +135,47 @@ describe('Line', function ()
             Line.prototype.setTo.call(obj);
             expect(geomSetTo).toHaveBeenCalledWith(undefined, undefined, undefined, undefined);
         });
+
+        it('should calculate width from the difference of x2 and x1', function ()
+        {
+            obj.width = 0;
+            Line.prototype.setTo.call(obj, 1, 2, 3, 5);
+            expect(obj.width).toBe(2);
+        });
+
+        it('should calculate height from the difference of y2 and y1', function ()
+        {
+            obj.height = 0;
+            Line.prototype.setTo.call(obj, 1, 2, 3, 5);
+            expect(obj.height).toBe(3);
+        });
+
+        it('should calculate the correct width when x2 < x1', function ()
+        {
+            obj.width = 0;
+            Line.prototype.setTo.call(obj, 5, 3, 2, 1);
+            expect(obj.width).toBe(3);
+        });
+
+        it('should calculate the correct height when y2 < y1', function ()
+        {
+            obj.height = 0;
+            Line.prototype.setTo.call(obj, 5, 3, 2, 1);
+            expect(obj.height).toBe(2);
+        });
+
+        it('should set width to 1 (not 0) when x1 equals x2', function ()
+        {
+            obj.width = 0;
+            Line.prototype.setTo.call(obj, 1, 2, 1, 5);
+            expect(obj.width).toBe(1);
+        });
+
+        it('should set height to 1 (not 0) when y1 equals y2', function ()
+        {
+            obj.height = 0;
+            Line.prototype.setTo.call(obj, 2, 1, 5, 1);
+            expect(obj.height).toBe(1);
+        });
     });
 });