diff --git a/webpack/plugins/svg-prep.js b/webpack/plugins/svg-prep.js
index a9399eb384..ab7caaf20f 100644
--- a/webpack/plugins/svg-prep.js
+++ b/webpack/plugins/svg-prep.js
@@ -10,6 +10,8 @@
 const fs = require('fs');
 const path = require('path');
 const SvgPrep = require('svg-prep');
+const { Compilation, sources } = require('webpack');
+const { RawSource } = sources;
 
 function SvgPrepPlugin(options) {
   this.options = {};
@@ -23,28 +25,28 @@ function SvgPrepPlugin(options) {
 }
 
 SvgPrepPlugin.prototype.apply = function(compiler) {
-  compiler.hooks.emit.tapAsync('SvgPrepPlugin', (compilation, callback) => {
-    if (!this.options.source) {
-      return callback();
-    }
+  compiler.hooks.thisCompilation.tap(SvgPrepPlugin.name, (compilation) => {
+    compilation.hooks.processAssets.tapPromise(
+      {
+        name: SvgPrepPlugin.name,
+        stage: Compilation.PROCESS_ASSETS_STAGE_ADDITIONAL,
+      },
+      async () => {
+        if (!this.options.source) {
+          return Promise.resolve();
+        }
 
-    // TODO: Keep track of file hashes, so we can avoid recompiling when none have changed
-    let files = fs.readdirSync(this.options.source).filter((name) => {
-      return !!name.match(/\.svg$/);
-    }).map((name) => path.join(this.options.source, name));
-    SvgPrep(files)
-      .filter({ removeIds: true, noFill: true })
-      .output().then((sprited) => {
-        compilation.assets[this.options.output] = {
-          source: function() {
-            return sprited;
-          },
-          size: function() {
-            return sprited.length;
-          }
-        };
+        // TODO: Keep track of file hashes, so we can avoid recompiling when none have changed
+        let files = fs
+          .readdirSync(this.options.source)
+          .filter((name) => name.endsWith('.svg'))
+          .map((name) => path.join(this.options.source, name));
 
-        callback();
+        const sprited = await SvgPrep(files)
+          .filter({ removeIds: true, noFill: true })
+          .output();
+
+        compilation.emitAsset(this.options.output, new RawSource(sprited));
       });
   });
 }