diff --git a/lib/svgo.js b/lib/svgo.js
index 1eacb4cf4..d93652fc3 100755
--- a/lib/svgo.js
+++ b/lib/svgo.js
@@ -23,7 +23,7 @@ const { encodeSVGDatauri } = require('./svgo/tools.js');
 
 exports.extendDefaultPlugins = extendDefaultPlugins;
 
-const optimize = (svgstr, config) => {
+const optimize = (input, config) => {
   if (config == null) {
     config = {};
   }
@@ -38,7 +38,8 @@ const optimize = (svgstr, config) => {
     info.path = config.path;
   }
   for (let i = 0; i < maxPassCount; i += 1) {
-    svgjs = svg2js(svgstr);
+    info.multipassCount = i;
+    svgjs = svg2js(input);
     if (svgjs.error == null) {
       const plugins = config.plugins || defaultPlugins;
       if (Array.isArray(plugins) === false) {
@@ -51,8 +52,8 @@ const optimize = (svgstr, config) => {
     if (svgjs.error) {
       throw Error(svgjs.error);
     }
-    info.multipassCount = i;
     if (svgjs.data.length < prevResultSize) {
+      input = svgjs.data;
       prevResultSize = svgjs.data.length
     } else {
       if (config.datauri) {
diff --git a/test/svgo/_index.js b/test/svgo/_index.js
index fa3ab9f0e..b2fd2169f 100644
--- a/test/svgo/_index.js
+++ b/test/svgo/_index.js
@@ -1,42 +1,49 @@
 'use strict';
 
 const { expect } = require('chai');
-const FS = require('fs');
-const PATH = require('path');
-const EOL = require('os').EOL;
-const regEOL = new RegExp(EOL, 'g');
-const { optimize } = require('../../lib/svgo.js');
-
-describe('indentation', function() {
-
-    it('should create indent with 2 spaces', function(done) {
-
-        var filepath = PATH.resolve(__dirname, './test.svg'),
-            svgo;
-
-        FS.readFile(filepath, 'utf8', function(err, data) {
-            if (err) {
-                throw err;
-            }
+const fs = require('fs');
+const path = require('path');
+const { EOL } = require('os');
+const { optimize, extendDefaultPlugins } = require('../../lib/svgo.js');
 
-            var splitted = normalize(data).split(/\s*@@@\s*/),
-                orig     = splitted[0],
-                should   = splitted[1];
-
-            const result = optimize(orig, {
-              path: filepath,
-              plugins : [],
-              js2svg  : { pretty: true, indent: 2 }
-            });
-            expect(normalize(result.data)).to.equal(should);
-            done();
-
-        });
-
-    });
+const regEOL = new RegExp(EOL, 'g');
 
+const normalize = (file) => {
+  return file.trim().replace(regEOL, '\n');
+};
+
+const parseFixture = async file => {
+  const filepath = path.resolve(__dirname, file);
+  const content = await fs.promises.readFile(filepath, 'utf-8');
+  return normalize(content).split(/\s*@@@\s*/);
+};
+
+describe('svgo', () => {
+  it('should create indent with 2 spaces', async () => {
+    const [original, expected] = await parseFixture('test.svg');
+      const result = optimize(original, {
+        plugins: [],
+        js2svg: { pretty: true, indent: 2 },
+      });
+      expect(normalize(result.data)).to.equal(expected);
+  });
+  it('should run multiple times', async () => {
+    const [original, expected] = await parseFixture('multipass.svg');
+      const result = optimize(original, {
+        multipass: true,
+      });
+      expect(normalize(result.data)).to.equal(expected);
+  });
+  it('should pass multipass count to plugins', async () => {
+    const [original, expected] = await parseFixture('multipass-prefix-ids.svg');
+      const result = optimize(original, {
+        multipass: true,
+        plugins: extendDefaultPlugins([
+          {
+            name: 'prefixIds',
+          },
+        ]),
+      });
+      expect(normalize(result.data)).to.equal(expected);
+  });
 });
-
-function normalize(file) {
-    return file.trim().replace(regEOL, '\n');
-}
diff --git a/test/svgo/multipass-prefix-ids.svg b/test/svgo/multipass-prefix-ids.svg
new file mode 100644
index 000000000..d61bcd8d9
--- /dev/null
+++ b/test/svgo/multipass-prefix-ids.svg
@@ -0,0 +1,7 @@
+<svg width="120" height="120" xmlns="http://www.w3.org/2000/svg">
+  <rect class="test" x="10" y="10" width="100" height="100"/>
+</svg>
+
+@@@
+
+<svg width="120" height="120" xmlns="http://www.w3.org/2000/svg"><path class="prefix__test" d="M10 10h100v100H10z"/></svg>
diff --git a/test/svgo/multipass.svg b/test/svgo/multipass.svg
new file mode 100644
index 000000000..424324b0b
--- /dev/null
+++ b/test/svgo/multipass.svg
@@ -0,0 +1,18 @@
+<!-- https://github.com/svg/svgo/pull/258#issue-23706813 -->
+<svg xmlns="http://www.w3.org/2000/svg">
+  <g transform="translate(-39, -239)">
+    <g id="test" class="test" transform="translate(39, 37)">
+      <g>
+        <rect id="Rectangle-1183" fill="#D4D4D4" x="8" y="223" width="7" height="19"></rect>
+        <rect id="Rectangle-1183" fill="#D4D4D4" x="4" y="227" width="42" height="3"></rect>
+        <rect id="Rectangle-1183" fill="#D0011B" x="23" y="227" width="6" height="3"></rect>
+        <rect id="Rectangle-1183" fill="#D0011B" x="35" y="227" width="6" height="3"></rect>
+        <rect id="Rectangle-1183" fill="#D0011B" x="11" y="227" width="6" height="3"></rect>
+      </g>
+    </g>
+  </g>
+</svg>
+
+@@@
+
+<svg xmlns="http://www.w3.org/2000/svg"><path fill="#D4D4D4" d="M8 21h7v19H8z"/><path fill="#D4D4D4" d="M4 25h42v3H4z"/><path fill="#D0011B" d="M23 25h6v3h-6zm12 0h6v3h-6zm-24 0h6v3h-6z"/></svg>