diff --git a/platform/chromium/manifest.json b/platform/chromium/manifest.json
index eae426f1f..a7361b27a 100644
--- a/platform/chromium/manifest.json
+++ b/platform/chromium/manifest.json
@@ -2,7 +2,7 @@
     "manifest_version": 2,
 
     "name": "uBlock Origin",
-    "version": "1.3.4",
+    "version": "1.3.5",
 
     "default_locale": "en",
     "description": "__MSG_extShortDesc__",
diff --git a/platform/firefox/vapi-background.js b/platform/firefox/vapi-background.js
index b622458e8..360cc5aad 100644
--- a/platform/firefox/vapi-background.js
+++ b/platform/firefox/vapi-background.js
@@ -2240,7 +2240,10 @@ vAPI.net.registerListeners = function() {
         var browser = e.target;
 
         // I have seen this happens (at startup time)
-        if ( !browser.currentURI ) {
+        // https://github.com/gorhill/uBlock/issues/948
+        //   On older version of Firefox, `browser.webNavigation` can be null,
+        //   which would cause currentURI to fail.
+        if ( !browser.webNavigation || !browser.currentURI ) {
             return;
         }
 
diff --git a/platform/opera/manifest.json b/platform/opera/manifest.json
index 6814c9635..0ce690e8a 100644
--- a/platform/opera/manifest.json
+++ b/platform/opera/manifest.json
@@ -2,7 +2,7 @@
     "manifest_version": 2,
 
     "name": "uBlock Origin",
-    "version": "1.3.4",
+    "version": "1.3.5",
 
     "default_locale": "en",
     "description": "__MSG_extShortDesc__",