diff --git a/app/build.sh b/app/build.sh
index 649d629..7d078b8 100755
--- a/app/build.sh
+++ b/app/build.sh
@@ -59,10 +59,7 @@ function abspath {
 }
 
 function check_lfs_file {
-	if [ "$(head --bytes 5 "$1")" = "versi" ]; then
-		echo "$1 not checked out -- install Git LFS and run 'git lfs pull'" >&2
-		exit 1
-	fi
+	return 0
 }
 
 SOURCE_DIR=""
@@ -840,18 +837,13 @@ if [ $BUILD_LINUX == 1 ]; then
 		cp -r "$runtime_path/"!(application.ini|browser|defaults|devtools-files|crashreporter|crashreporter.ini|firefox|pingsender|precomplete|removed-files|run-mozilla.sh|update-settings.ini|updater|updater.ini) "$APPDIR"
 		
 		# Use our own launcher that calls the original Firefox executable with -app
-		mv "$APPDIR"/firefox-bin "$APPDIR"/zotero-bin
+		mv "$APPDIR"/firefox-esr "$APPDIR"/zotero-bin
 		cp "$CALLDIR/linux/zotero" "$APPDIR"/zotero
 		
 		# Copy Ubuntu launcher files
 		cp "$CALLDIR/linux/zotero.desktop" "$APPDIR"
 		cp "$CALLDIR/linux/set_launcher_icon" "$APPDIR"
 		
-		# Use our own updater, because Mozilla's requires updates signed by Mozilla
-		check_lfs_file "$CALLDIR/linux/updater.tar.xz"
-		tar xf "$CALLDIR/linux/updater.tar.xz" --to-stdout updater-$arch > "$APPDIR/updater"
-		chmod 755 "$APPDIR/updater"
-
 		# Copy app files
 		rsync -a "$base_dir/" "$APPDIR/"
 		
@@ -860,6 +852,7 @@ if [ $BUILD_LINUX == 1 ]; then
 		cp -RH "$CALLDIR/modules/zotero-libreoffice-integration/install" "$APPDIR/integration/libreoffice"
 		
 		# Copy icons
+		mkdir -p "$APPDIR"/icons
 		cp "$CALLDIR/linux/icons/icon32.png" "$APPDIR/icons/"
 		cp "$CALLDIR/linux/icons/icon64.png" "$APPDIR/icons/"
 		cp "$CALLDIR/linux/icons/icon128.png" "$APPDIR/icons/"
 		
diff --git a/app/scripts/fetch_xulrunner b/app/scripts/fetch_xulrunner
index 8b3d918..120b085 100755
--- a/app/scripts/fetch_xulrunner
+++ b/app/scripts/fetch_xulrunner
@@ -132,15 +132,6 @@ function modify_omni {
 	# Continue using app.update.auto in prefs.js on Windows
 	replace_line 'PER_INSTALLATION_PREFS_PLATFORMS = \["win"\]' 'PER_INSTALLATION_PREFS_PLATFORMS = []' modules/UpdateUtils.jsm
 	
-	# Prompt if major update is available instead of installing automatically on restart
-	replace_line 'if \(!updateAuto\) \{' 'if (update.type == "major") {
-      LOG("UpdateService:_selectAndInstallUpdate - prompting because it is a major update");
-      AUSTLMY.pingCheckCode(this._pingSuffix, AUSTLMY.CHK_SHOWPROMPT_PREF);
-      Services.obs.notifyObservers(update, "update-available", "show-prompt");
-      return;
-    }
-    if (!updateAuto) {' modules/UpdateService.jsm
-	
 	# Avoid console warning about resource://gre/modules/FxAccountsCommon.js
 	replace_line 'const logins = this._data.logins;' 'const logins = this._data.logins; if (this._data.logins.length != -1) return;' modules/LoginStore.jsm
 	
@@ -470,36 +461,11 @@ fi
 
 if [ $BUILD_LINUX == 1 ]; then
 	GECKO_VERSION="$GECKO_VERSION_LINUX"
-	DOWNLOAD_URL="https://ftp.mozilla.org/pub/firefox/releases/$GECKO_VERSION"
 
+ 	pushd firefox-x86_64
+ 	modify_omni linux64
+ 	popd
 
-	# Include 32-bit build if not in CI
-	if [[ "${CI:-}" = "1" ]] || [[ "${SKIP_32:-}" = "1" ]]; then
-		arches="x86_64"
-	else
-		arches="i686 x86_64"
-	fi
-	for arch in $arches; do
-		xdir="firefox-$arch"
-		rm -rf $xdir
-		
-		archived_file="firefox-$GECKO_VERSION-$arch.tar.bz2"
-		if [ -e "$archived_file" ]; then
-			echo "Using $archived_file"
-			cp "$archived_file" "firefox-$GECKO_VERSION.tar.bz2"
-		else
-			curl -O "$DOWNLOAD_URL/linux-$arch/en-US/firefox-$GECKO_VERSION.tar.bz2"
-		fi
-
-		tar xvf firefox-$GECKO_VERSION.tar.bz2
-		mv firefox firefox-$arch
-
-		pushd firefox-$arch
-		modify_omni
-		popd
-		echo $($SCRIPT_DIR/xulrunner_hash -p l) > hash-linux
-		rm "firefox-$GECKO_VERSION.tar.bz2"
-	done
 fi
 
 echo Done