diff --git a/app/src/main/java/com/topjohnwu/magisk/asyncs/RestoreStockBoot.java b/app/src/main/java/com/topjohnwu/magisk/asyncs/RestoreStockBoot.java
index fd6717c0d..6854e28c4 100644
--- a/app/src/main/java/com/topjohnwu/magisk/asyncs/RestoreStockBoot.java
+++ b/app/src/main/java/com/topjohnwu/magisk/asyncs/RestoreStockBoot.java
@@ -19,10 +19,18 @@ public class RestoreStockBoot extends ParallelTask<Void, Void, Boolean> {
 
     @Override
     protected Boolean doInBackground(Void... voids) {
-        List<String> ret = Shell.su("cat /init.magisk.rc | grep STOCKSHA1");
-        if (!Utils.isValidShellResponse(ret))
-            return false;
-        String stock_boot = "/data/stock_boot_" + ret.get(0).substring(ret.get(0).indexOf('=') + 1) + ".img.gz";
+        String sha1;
+        List<String> ret = Utils.readFile("/.backup/.sha1");
+        if (!Utils.isValidShellResponse(ret)) {
+            ret = Shell.su("cat /init.magisk.rc | grep STOCKSHA1");
+            if (!Utils.isValidShellResponse(ret))
+                return false;
+            sha1 = ret.get(0).substring(ret.get(0).indexOf('=') + 1);
+        } else {
+            sha1 = ret.get(0);
+        }
+
+        String stock_boot = "/data/stock_boot_" + sha1 + ".img.gz";
         if (!Utils.itemExist(stock_boot))
             return false;
         Shell.su_raw("flash_boot_image " + stock_boot + " " + mBoot);