diff --git a/.babelrc b/.babelrc
index cfedf764ce..a17f10849f 100644
--- a/.babelrc
+++ b/.babelrc
@@ -9,7 +9,8 @@
     // obeys the spec more, but we get a bundle that's 8kB larger. That was the
     // default in babel v6.
     ["@babel/plugin-proposal-class-properties", { loose: true }],
-    ["@babel/plugin-proposal-object-rest-spread", { useBuiltIns: true }]
+    ["@babel/plugin-proposal-object-rest-spread", { useBuiltIns: true }],
+    "syntax-dynamic-import"
   ],
   env: {
     test: {
@@ -20,8 +21,9 @@
       ],
       plugins: [
         ["@babel/plugin-proposal-class-properties", { loose: true }],
-        ["@babel/plugin-proposal-object-rest-spread", { useBuiltIns: true }]
-      ]
+        ["@babel/plugin-proposal-object-rest-spread", { useBuiltIns: true }],
+        "dynamic-import-node"
+      ],
     }
   }
 }
diff --git a/__mocks__/gecko-profiler-demangle.js b/__mocks__/gecko-profiler-demangle.js
new file mode 100644
index 0000000000..c6aaf0d2de
--- /dev/null
+++ b/__mocks__/gecko-profiler-demangle.js
@@ -0,0 +1,21 @@
+// This module replaces the wasm-pack generated module 'gecko-profiler-demangle'
+// in our tests.
+// The reason for this replacement is the fact that wasm-pack (or rather,
+// wasm-bindgen), when targeting the browser + webpack, generates an ES6 module
+// that node cannot deal with. Most importantly, it uses the syntax
+// "import * as wasm from './gecko_profiler_demangle_bg';" in order to load
+// the wasm module, which is currently only supported by webpack.
+// The long-term path to make this work correctly is to wait for node to
+// support ES6 modules (and WASM as ES6 modules) natively [1]. It's possible
+// that in the medium term, wasm-bindgen will get support for outputting JS
+// files which work in both webpack and in node natively [2].
+// [1] https://medium.com/@giltayar/native-es-modules-in-nodejs-status-and-future-directions-part-i-ee5ea3001f71
+// [2] https://github.com/rustwasm/wasm-bindgen/issues/233
+
+// @flow
+
+// There's only one exported function.
+// Do the simplest thing possible: no demangling.
+export function demangle_any(s: string): string {
+  return s;
+}
diff --git a/package.json b/package.json
index 67fec176bf..8bb35739dc 100644
--- a/package.json
+++ b/package.json
@@ -39,16 +39,20 @@
   "dependencies": {
     "array-move": "^1.0.0",
     "array-range": "^1.0.1",
+    "babel-plugin-dynamic-import-node": "^2.0.0",
+    "babel-plugin-syntax-dynamic-import": "^6.18.0",
+    "babel-runtime": "^6.26.0",
     "bisection": "0.0.3",
     "clamp": "^1.0.1",
     "classnames": "^2.2.5",
     "common-tags": "^1.7.2",
     "copy-to-clipboard": "^3.0.8",
     "escape-string-regexp": "^1.0.5",
+    "gecko-profiler-demangle": "^0.1.0",
     "jszip": "^3.1.5",
     "memoize-immutable": "^3.0.0",
     "mixedtuplemap": "^1.0.0",
-    "offline-plugin": "^5.0.5",
+    "@mstange/offline-plugin": "^5.0.6",
     "photon-colors": "2.0.1",
     "prop-types": "^15.6.0",
     "query-string": "^5.1.0",
diff --git a/src/index.js b/src/index.js
index f13737ef8f..7d772b78a0 100644
--- a/src/index.js
+++ b/src/index.js
@@ -27,7 +27,10 @@ if (process.env.NODE_ENV === 'development') {
 }
 
 if (process.env.NODE_ENV === 'production') {
-  const runtime = require('offline-plugin/runtime');
+  // We use '@mstange/offline-plugin/runtime' here instead of
+  // 'offline-plugin/runtime' because the fork contains the fix from
+  // https://github.com/NekR/offline-plugin/pull/410
+  const runtime = require('@mstange/offline-plugin/runtime');
   runtime.install({
     onUpdateReady: () => {
       runtime.applyUpdate();
diff --git a/src/profile-logic/symbol-store.js b/src/profile-logic/symbol-store.js
index 153c06c261..fbae9d3483 100644
--- a/src/profile-logic/symbol-store.js
+++ b/src/profile-logic/symbol-store.js
@@ -7,6 +7,8 @@ import SymbolStoreDB from './symbol-store-db';
 import { SymbolsNotFoundError } from './errors';
 import bisection from 'bisection';
 
+const demangleModulePromise = import('gecko-profiler-demangle');
+
 import type { RequestedLib } from '../types/actions';
 import type { SymbolTableAsTuple } from './symbol-store-db';
 
@@ -117,7 +119,8 @@ export class SymbolStore {
   // This format is documented at the SymbolTableAsTuple flow type definition.
   _readSymbolsFromSymbolTable(
     addresses: Set<number>,
-    symbolTable: SymbolTableAsTuple
+    symbolTable: SymbolTableAsTuple,
+    demangleCallback: string => string
   ): Map<number, AddressResult> {
     const [symbolTableAddrs, symbolTableIndex, symbolTableBuffer] = symbolTable;
     const addressArray = Uint32Array.from(addresses);
@@ -154,7 +157,9 @@ export class SymbolStore {
           const startOffset = symbolTableIndex[symbolIndex];
           const endOffset = symbolTableIndex[symbolIndex + 1];
           const subarray = symbolTableBuffer.subarray(startOffset, endOffset);
-          currentSymbol = decoder.decode(subarray);
+          // C++ or rust symbols in the symbol table may have mangled names.
+          // Demangle them here.
+          currentSymbol = demangleCallback(decoder.decode(subarray));
           currentSymbolIndex = symbolIndex;
         }
         results.set(address, {
@@ -272,10 +277,16 @@ export class SymbolStore {
     // symbolication for the libraries for which we found symbol tables in the
     // database. This is delayed until after the request has been kicked off
     // because it can take some time.
+    // We also need a demangling function for this, which is in an async module.
+    const demangleCallback = (await demangleModulePromise).demangle_any;
     for (const { request, symbolTable } of requestsForCachedLibs) {
       successCb(
         request,
-        this._readSymbolsFromSymbolTable(request.addresses, symbolTable)
+        this._readSymbolsFromSymbolTable(
+          request.addresses,
+          symbolTable,
+          demangleCallback
+        )
       );
     }
 
@@ -316,7 +327,11 @@ export class SymbolStore {
             // Did not throw, option 3 was successful!
             successCb(
               request,
-              this._readSymbolsFromSymbolTable(addresses, symbolTable)
+              this._readSymbolsFromSymbolTable(
+                addresses,
+                symbolTable,
+                demangleCallback
+              )
             );
 
             // Store the symbol table in the database.
diff --git a/src/types/libdef/npm/@mstange/offline-plugin_vx.x.x.js b/src/types/libdef/npm/@mstange/offline-plugin_vx.x.x.js
new file mode 100644
index 0000000000..ee948990b1
--- /dev/null
+++ b/src/types/libdef/npm/@mstange/offline-plugin_vx.x.x.js
@@ -0,0 +1,137 @@
+// flow-typed signature: f84c93c5335ad9c36684cc95ca54b099
+// flow-typed version: <<STUB>>/@mstange/offline-plugin_v^5.0.6/flow_v0.70.0
+
+/**
+ * This is an autogenerated libdef stub for:
+ *
+ *   '@mstange/offline-plugin'
+ *
+ * Fill this stub out by replacing all the `any` types.
+ *
+ * Once filled out, we encourage you to share your work with the
+ * community by sending a pull request to:
+ * https://github.com/flowtype/flow-typed
+ */
+
+declare module '@mstange/offline-plugin' {
+  declare module.exports: any;
+}
+
+/**
+ * We include stubs for each file inside this npm package in case you need to
+ * require those files directly. Feel free to delete any files that aren't
+ * needed.
+ */
+declare module '@mstange/offline-plugin/lib/app-cache' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/default-options' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/index' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/loaders/fonts-css' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/loaders/index' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/misc/async-waituntil' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/misc/get-uglify-plugin' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/misc/runtime-loader' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/misc/sw-loader' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/misc/sw-polyfill' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/misc/sw-template' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/misc/utils' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/lib/service-worker' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/runtime' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/tpls/empty-entry' {
+  declare module.exports: any;
+}
+
+declare module '@mstange/offline-plugin/tpls/runtime-template' {
+  declare module.exports: any;
+}
+
+// Filename aliases
+declare module '@mstange/offline-plugin/lib/app-cache.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/app-cache'>;
+}
+declare module '@mstange/offline-plugin/lib/default-options.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/default-options'>;
+}
+declare module '@mstange/offline-plugin/lib/index.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/index'>;
+}
+declare module '@mstange/offline-plugin/lib/loaders/fonts-css.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/loaders/fonts-css'>;
+}
+declare module '@mstange/offline-plugin/lib/loaders/index.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/loaders/index'>;
+}
+declare module '@mstange/offline-plugin/lib/misc/async-waituntil.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/misc/async-waituntil'>;
+}
+declare module '@mstange/offline-plugin/lib/misc/get-uglify-plugin.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/misc/get-uglify-plugin'>;
+}
+declare module '@mstange/offline-plugin/lib/misc/runtime-loader.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/misc/runtime-loader'>;
+}
+declare module '@mstange/offline-plugin/lib/misc/sw-loader.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/misc/sw-loader'>;
+}
+declare module '@mstange/offline-plugin/lib/misc/sw-polyfill.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/misc/sw-polyfill'>;
+}
+declare module '@mstange/offline-plugin/lib/misc/sw-template.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/misc/sw-template'>;
+}
+declare module '@mstange/offline-plugin/lib/misc/utils.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/misc/utils'>;
+}
+declare module '@mstange/offline-plugin/lib/service-worker.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/lib/service-worker'>;
+}
+declare module '@mstange/offline-plugin/runtime.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/runtime'>;
+}
+declare module '@mstange/offline-plugin/tpls/empty-entry.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/tpls/empty-entry'>;
+}
+declare module '@mstange/offline-plugin/tpls/runtime-template.js' {
+  declare module.exports: $Exports<'@mstange/offline-plugin/tpls/runtime-template'>;
+}
diff --git a/src/types/libdef/npm/gecko-profiler-demangle_vx.x.x.js b/src/types/libdef/npm/gecko-profiler-demangle_vx.x.x.js
new file mode 100644
index 0000000000..641e62c0d2
--- /dev/null
+++ b/src/types/libdef/npm/gecko-profiler-demangle_vx.x.x.js
@@ -0,0 +1,32 @@
+// flow-typed signature: e6f43a673a1ad489aea31817e5e11e45
+// flow-typed version: <<STUB>>/gecko-profiler-demangle_v^0.1.0/flow_v0.70.0
+
+/**
+ * This is an autogenerated libdef stub for:
+ *
+ *   'gecko-profiler-demangle'
+ *
+ * Fill this stub out by replacing all the `any` types.
+ *
+ * Once filled out, we encourage you to share your work with the
+ * community by sending a pull request to:
+ * https://github.com/flowtype/flow-typed
+ */
+
+declare module 'gecko-profiler-demangle' {
+  declare module.exports: any;
+}
+
+/**
+ * We include stubs for each file inside this npm package in case you need to
+ * require those files directly. Feel free to delete any files that aren't
+ * needed.
+ */
+declare module 'gecko-profiler-demangle/gecko_profiler_demangle' {
+  declare module.exports: any;
+}
+
+// Filename aliases
+declare module 'gecko-profiler-demangle/gecko_profiler_demangle.js' {
+  declare module.exports: $Exports<'gecko-profiler-demangle/gecko_profiler_demangle'>;
+}
diff --git a/webpack.config.js b/webpack.config.js
index 39d213758b..de6005f115 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -2,7 +2,7 @@
 const path = require('path');
 const webpack = require('webpack');
 const HtmlWebpackPlugin = require('html-webpack-plugin');
-const OfflinePlugin = require('offline-plugin');
+const OfflinePlugin = require('@mstange/offline-plugin');
 const CopyWebpackPlugin = require('copy-webpack-plugin');
 const includes = [path.join(__dirname, 'src'), path.join(__dirname, 'res')];
 
@@ -18,7 +18,7 @@ const config = {
       'redux-devtools': path.join(__dirname, '..', '..', 'src'),
       react: path.join(__dirname, 'node_modules', 'react'),
     },
-    extensions: ['.js'],
+    extensions: ['.js', '.wasm'],
   },
   devtool: 'source-map',
   module: {
@@ -79,6 +79,10 @@ const config = {
     chunkFilename: '[id].[hash].bundle.js',
     publicPath: '/',
   },
+  optimization: {
+    // Workaround for https://github.com/webpack/webpack/issues/7760
+    usedExports: false,
+  },
 };
 
 if (process.env.NODE_ENV === 'development') {
diff --git a/yarn.lock b/yarn.lock
index ac3c524817..4223bd5b13 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -647,6 +647,16 @@
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/@koa/cors/-/cors-2.2.1.tgz#c06a1c34d787e3cee79c0d4c20e8952d1b6d75c5"
 
+"@mstange/offline-plugin@^5.0.6":
+  version "5.0.6"
+  resolved "https://registry.yarnpkg.com/@mstange/offline-plugin/-/offline-plugin-5.0.6.tgz#23d90b9e33fb5546f4b7082ba62796919e0aabb3"
+  dependencies:
+    deep-extend "^0.5.1"
+    ejs "^2.3.4"
+    loader-utils "0.2.x"
+    minimatch "^3.0.3"
+    slash "^1.0.0"
+
 "@sinonjs/formatio@^2.0.0":
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/@sinonjs/formatio/-/formatio-2.0.0.tgz#84db7e9eb5531df18a8c5e0bfb6e449e55e654b2"
@@ -1349,6 +1359,13 @@ babel-messages@^6.23.0:
   dependencies:
     babel-runtime "^6.22.0"
 
+babel-plugin-dynamic-import-node@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-dynamic-import-node/-/babel-plugin-dynamic-import-node-2.0.0.tgz#d6fc3f6c5e3bdc34e49c15faca7ce069755c0a57"
+  dependencies:
+    babel-plugin-syntax-dynamic-import "^6.18.0"
+    object.assign "^4.1.0"
+
 babel-plugin-istanbul@^4.1.6:
   version "4.1.6"
   resolved "https://registry.yarnpkg.com/babel-plugin-istanbul/-/babel-plugin-istanbul-4.1.6.tgz#36c59b2192efce81c5b378321b74175add1c9a45"
@@ -1362,6 +1379,10 @@ babel-plugin-jest-hoist@^23.2.0:
   version "23.2.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-jest-hoist/-/babel-plugin-jest-hoist-23.2.0.tgz#e61fae05a1ca8801aadee57a6d66b8cefaf44167"
 
+babel-plugin-syntax-dynamic-import@^6.18.0:
+  version "6.18.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-syntax-dynamic-import/-/babel-plugin-syntax-dynamic-import-6.18.0.tgz#8d6a26229c83745a9982a441051572caa179b1da"
+
 babel-plugin-syntax-object-rest-spread@^6.13.0, babel-plugin-syntax-object-rest-spread@^6.8.0:
   version "6.13.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-syntax-object-rest-spread/-/babel-plugin-syntax-object-rest-spread-6.13.0.tgz#fd6536f2bce13836ffa3a5458c4903a597bb3bf5"
@@ -4110,6 +4131,10 @@ gauge@~2.7.3:
     strip-ansi "^3.0.1"
     wide-align "^1.1.0"
 
+gecko-profiler-demangle@^0.1.0:
+  version "0.1.0"
+  resolved "https://registry.yarnpkg.com/gecko-profiler-demangle/-/gecko-profiler-demangle-0.1.0.tgz#7bc08d43e3572e64a6c09c4ed6680e4bc4ce356e"
+
 get-caller-file@^1.0.1:
   version "1.0.3"
   resolved "https://registry.yarnpkg.com/get-caller-file/-/get-caller-file-1.0.3.tgz#f978fa4c90d1dfe7ff2d6beda2a515e713bdcf4a"
@@ -6989,16 +7014,6 @@ obuf@^1.0.0, obuf@^1.1.1:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/obuf/-/obuf-1.1.1.tgz#104124b6c602c6796881a042541d36db43a5264e"
 
-offline-plugin@^5.0.5:
-  version "5.0.5"
-  resolved "https://registry.yarnpkg.com/offline-plugin/-/offline-plugin-5.0.5.tgz#e9b16c569d19899af9c923f5bc260705578ffeba"
-  dependencies:
-    deep-extend "^0.5.1"
-    ejs "^2.3.4"
-    loader-utils "0.2.x"
-    minimatch "^3.0.3"
-    slash "^1.0.0"
-
 on-finished@^2.3.0, on-finished@~2.3.0:
   version "2.3.0"
   resolved "https://registry.yarnpkg.com/on-finished/-/on-finished-2.3.0.tgz#20f1336481b083cd75337992a16971aa2d906947"