diff --git a/browser_patches/firefox/BUILD_NUMBER b/browser_patches/firefox/BUILD_NUMBER
index bba0bc80a9..cf635ffb9e 100644
--- a/browser_patches/firefox/BUILD_NUMBER
+++ b/browser_patches/firefox/BUILD_NUMBER
@@ -1 +1 @@
-1073
+1074
diff --git a/browser_patches/firefox/patches/bootstrap.diff b/browser_patches/firefox/patches/bootstrap.diff
index 3444207a39..9ab19e3aef 100644
--- a/browser_patches/firefox/patches/bootstrap.diff
+++ b/browser_patches/firefox/patches/bootstrap.diff
@@ -2953,10 +2953,10 @@ index 0000000000000000000000000000000000000000..268fbc361d8053182bb6c27f626e853d
 +
 diff --git a/juggler/content/FrameTree.js b/juggler/content/FrameTree.js
 new file mode 100644
-index 0000000000000000000000000000000000000000..5a1df2837d70531a670163b7c860108895bc9106
+index 0000000000000000000000000000000000000000..8a87dabd37e83cba0f1dfac07d8fd18875c042ef
 --- /dev/null
 +++ b/juggler/content/FrameTree.js
-@@ -0,0 +1,462 @@
+@@ -0,0 +1,471 @@
 +"use strict";
 +const Ci = Components.interfaces;
 +const Cr = Components.results;
@@ -3149,12 +3149,19 @@ index 0000000000000000000000000000000000000000..5a1df2837d70531a670163b7c8601088
 +    const isTransferring = flag & Ci.nsIWebProgressListener.STATE_TRANSFERRING;
 +    const isStop = flag & Ci.nsIWebProgressListener.STATE_STOP;
 +
++    let isDownload = false;
++    try {
++      isDownload = (channel.contentDisposition === Ci.nsIChannel.DISPOSITION_ATTACHMENT);
++    } catch(e) {
++      // The method is expected to throw if it's not an attachment.
++    }
++
 +    if (isStart) {
 +      // Starting a new navigation.
 +      frame._pendingNavigationId = this._channelId(channel);
 +      frame._pendingNavigationURL = channel.URI.spec;
 +      this.emit(FrameTree.Events.NavigationStarted, frame);
-+    } else if (isTransferring || (isStop && frame._pendingNavigationId && !status)) {
++    } else if (isTransferring || (isStop && frame._pendingNavigationId && !status && !isDownload)) {
 +      // Navigation is committed.
 +      for (const subframe of frame._children)
 +        this._detachFrame(subframe);
@@ -3166,12 +3173,14 @@ index 0000000000000000000000000000000000000000..5a1df2837d70531a670163b7c8601088
 +      this.emit(FrameTree.Events.NavigationCommitted, frame);
 +      if (frame === this._mainFrame)
 +        this.forcePageReady();
-+    } else if (isStop && frame._pendingNavigationId && status) {
++    } else if (isStop && frame._pendingNavigationId && (status || isDownload)) {
 +      // Navigation is aborted.
 +      const navigationId = frame._pendingNavigationId;
 +      frame._pendingNavigationId = null;
 +      frame._pendingNavigationURL = null;
-+      this.emit(FrameTree.Events.NavigationAborted, frame, navigationId, helper.getNetworkErrorStatusText(status));
++      // Always report download navigation as failure to match other browsers.
++      const errorText = isDownload ? 'Will download to file' : helper.getNetworkErrorStatusText(status);
++      this.emit(FrameTree.Events.NavigationAborted, frame, navigationId, errorText);
 +    }
 +  }
 +