diff --git a/editor.js b/editor.js
index a423bbfac..6d17babaf 100644
--- a/editor.js
+++ b/editor.js
@@ -1436,7 +1436,7 @@ class MenuBar extends QinoqMorph {
   }
 }
 
-class Settings extends QinoqMorph {
+export class Settings extends QinoqMorph {
   static get properties () {
     return {
       name: {
@@ -1549,7 +1549,8 @@ class Settings extends QinoqMorph {
 
   inputLineUpdate (input) {
     try {
-      const newRatio = eval(input);
+      const newRatio = Settings.matchNumberOrFraction(input);
+      if (!newRatio) throw new Error('The input was not a number!');
       this.interactive.fixedAspectRatio = newRatio;
       this.editor.onInteractiveZoomed();
       success('Ratio updated!');
@@ -1558,6 +1559,15 @@ class Settings extends QinoqMorph {
     }
   }
 
+  static matchNumberOrFraction (inputString) {
+    // eslint-disable-next-line no-useless-escape
+    const match = inputString.match(RegExp('^(\\d+)((\\.\\d+)|(\\/\\d+))?$', 'i'));
+    if (!match) return null;
+    if (!match[2]) return Number(match[1]);
+    if (match[2].includes('.')) return Number(match[1].concat(match[3]));
+    if (match[2].includes('/')) return Number(match[1]) / Number(match[4].substring(1));
+  }
+
   dropDownSelectorUpdate (input) {
     if (input == 'Custom') {
       this.ui.inputLine.visible = true;
diff --git a/tests/settings-test.js b/tests/settings-test.js
new file mode 100644
index 000000000..0bc2872f6
--- /dev/null
+++ b/tests/settings-test.js
@@ -0,0 +1,23 @@
+/* global it, describe */
+import { expect } from 'mocha-es6';
+import { Settings } from '../editor.js';
+
+describe('Settings', () => {
+  it('parses fractions and numbers in correct formats', () => {
+    expect(Settings.matchNumberOrFraction('3')).to.be.equal(3);
+    expect(Settings.matchNumberOrFraction('4/3')).to.be.equal(4 / 3);
+    expect(Settings.matchNumberOrFraction('3.5')).to.be.equal(3.5);
+    expect(Settings.matchNumberOrFraction('3123.123')).to.be.equal(3123.123);
+    expect(Settings.matchNumberOrFraction('3123/123')).to.be.equal(3123 / 123);
+  });
+
+  it('parses fractions and numbers in incorrect formats', () => {
+    expect(Settings.matchNumberOrFraction('123/456.789')).to.be.null;
+    expect(Settings.matchNumberOrFraction('123.456/789')).to.be.null;
+    expect(Settings.matchNumberOrFraction('3.')).to.be.null;
+    expect(Settings.matchNumberOrFraction('3/')).to.be.null;
+    expect(Settings.matchNumberOrFraction('[3/4]')).to.be.null;
+    expect(Settings.matchNumberOrFraction('[3/')).to.be.null;
+    expect(Settings.matchNumberOrFraction('{3/}')).to.be.null;
+  });
+});