diff --git a/platform/webext/bootstrap.js b/platform/webext/bootstrap.js
index 69f6fc7dd..ebbbc0b78 100644
--- a/platform/webext/bootstrap.js
+++ b/platform/webext/bootstrap.js
@@ -46,6 +46,9 @@ function startup({ webExtension }) {
                 });
                 return true;
             }
+            if ( message.what === 'webext:storageMigrateDone' ) {
+                browser.runtime.onMessage.removeListener(onMessage);
+            }
             if ( typeof callback === 'function' ) {
                 callback();
             }
@@ -262,13 +265,6 @@ var getStorageMigrator = function() {
 
     let markAsDone = function() {
         close();
-        let { Services } = Components.utils.import('resource://gre/modules/Services.jsm', null),
-            path = Services.dirsvc.get('ProfD', Components.interfaces.nsIFile);
-        path.append('extension-data');
-        path.append(hostName + '.sqlite');
-        if ( path.exists() && path.isFile() ) {
-            path.renameTo(null, hostName + '.migrated.sqlite');
-        }
     };
 
     return {
diff --git a/platform/webext/from-legacy.js b/platform/webext/from-legacy.js
index 456086536..93edba2be 100644
--- a/platform/webext/from-legacy.js
+++ b/platform/webext/from-legacy.js
@@ -52,7 +52,14 @@
             });
         };
 
-        migrateNext();
+        self.browser.storage.local.get('legacyStorageMigrated', bin => {
+            if ( bin && bin.legacyStorageMigrated ) {
+                self.browser.runtime.sendMessage({ what: 'webext:storageMigrateDone' });
+                return callback();
+            }
+            self.browser.storage.local.set({ legacyStorageMigrated: true });
+            migrateNext();
+        });
     };
 
     µb.onBeforeStartQueue.push(migrateAll);