diff --git a/toolkit/modules/GMPExtractorWorker.js b/toolkit/modules/GMPExtractorWorker.js
index d4835da90d22..6f1ff8f9c052 100644
--- a/toolkit/modules/GMPExtractorWorker.js
+++ b/toolkit/modules/GMPExtractorWorker.js
@@ -13,7 +13,9 @@ const FILE_ENTRY = "201: ";
 onmessage = async function(msg) {
   try {
     let extractedPaths = [];
-    let jarPath = "jar:file://" + msg.data.zipPath + "!/";
+    // Construct a jar URI from the file URI so we can use the JAR URI scheme
+    // handling to navigate inside the zip file.
+    let jarPath = "jar:" + msg.data.zipURI + "!/";
     let jarResponse = await fetch(jarPath);
     let dirListing = await jarResponse.text();
     let lines = dirListing.split("\n");
diff --git a/toolkit/modules/GMPInstallManager.jsm b/toolkit/modules/GMPInstallManager.jsm
index 06f12c2f8988..4b1e3ff6c311 100644
--- a/toolkit/modules/GMPInstallManager.jsm
+++ b/toolkit/modules/GMPInstallManager.jsm
@@ -34,6 +34,11 @@ ChromeUtils.defineModuleGetter(
   "CertUtils",
   "resource://gre/modules/CertUtils.jsm"
 );
+ChromeUtils.defineModuleGetter(
+  this,
+  "FileUtils",
+  "resource://gre/modules/FileUtils.jsm"
+);
 ChromeUtils.defineModuleGetter(
   this,
   "UpdateUtils",
@@ -506,8 +511,10 @@ GMPAddon.prototype = {
 };
 /**
  * Constructs a GMPExtractor object which is used to extract a GMP zip
- * into the specified location. (Which typically leties per platform)
+ * into the specified location.
  * @param zipPath The path on disk of the zip file to extract
+ * @param relativePath The relative path inside the profile directory to
+ * extract the zip to.
  */
 function GMPExtractor(zipPath, relativeInstallPath) {
   this.zipPath = zipPath;
@@ -525,6 +532,9 @@ GMPExtractor.prototype = {
     this._deferred = PromiseUtils.defer();
     let deferredPromise = this._deferred;
     let { zipPath, relativeInstallPath } = this;
+    // Escape the zip path since the worker will use it as a URI
+    let zipFile = new FileUtils.File(zipPath);
+    let zipURI = Services.io.newFileURI(zipFile).spec;
     let worker = new ChromeWorker(
       "resource://gre/modules/GMPExtractorWorker.js"
     );
@@ -532,17 +542,17 @@ GMPExtractor.prototype = {
       let log = getScopedLogger("GMPExtractor");
       worker.terminate();
       if (msg.data.result != "success") {
-        log.error("Failed to extract zip file: " + zipPath);
+        log.error("Failed to extract zip file: " + zipURI);
         return deferredPromise.reject({
           target: this,
           status: msg.data.exception,
           type: "exception",
         });
       }
-      log.info("Successfully extracted zip file: " + zipPath);
+      log.info("Successfully extracted zip file: " + zipURI);
       return deferredPromise.resolve(msg.data.extractedPaths);
     };
-    worker.postMessage({ zipPath, relativeInstallPath });
+    worker.postMessage({ zipURI, relativeInstallPath });
     return this._deferred.promise;
   },
 };