diff --git a/lib/read-wasm.js b/lib/read-wasm.js
index a4fb29c295516..75d7bd54153ad 100644
--- a/lib/read-wasm.js
+++ b/lib/read-wasm.js
@@ -1,22 +1,45 @@
 "use strict";
 
+const isNode =
+  typeof process !== "undefined" &&
+  process.versions != null &&
+  process.versions.node != null;
+
 let mappingsWasm = null;
 
-module.exports = function readWasm() {
-  if (typeof mappingsWasm === "string") {
-    return fetch(mappingsWasm).then(response => response.arrayBuffer());
-  }
-  if (mappingsWasm instanceof ArrayBuffer) {
-    return Promise.resolve(mappingsWasm);
-  }
+if (isNode) {
+  const fs = require("fs");
+  const path = require("path");
 
-  throw new Error(
-    "You must provide the string URL or ArrayBuffer contents " +
-      "of lib/mappings.wasm by calling " +
-      "SourceMapConsumer.initialize({ 'lib/mappings.wasm': ... }) " +
-      "before using SourceMapConsumer"
-  );
-};
+  module.exports = function readWasm() {
+    return new Promise((resolve, reject) => {
+      const wasmPath = path.join(__dirname, "mappings.wasm");
+      fs.readFile(wasmPath, null, (error, data) => {
+        if (error) {
+          reject(error);
+          return;
+        }
+
+        resolve(data.buffer);
+      });
+    });
+  };
+} else {
+  module.exports = function readWasm() {
+    if (typeof mappingsWasm === "string") {
+      return fetch(mappingsWasm)
+        .then(response => response.arrayBuffer());
+    }
+    if (mappingsWasm instanceof ArrayBuffer) {
+      return Promise.resolve(mappingsWasm);
+    }
+
+    throw new Error("You must provide the string URL or ArrayBuffer contents " +
+                    "of lib/mappings.wasm by calling " +
+                    "SourceMapConsumer.initialize({ 'lib/mappings.wasm': ... }) " +
+                    "before using SourceMapConsumer");
+  };
+}
 
 module.exports.initialize = input => {
   mappingsWasm = input;