diff --git a/electrum/gui/qt/qrreader/__init__.py b/electrum/gui/qt/qrreader/__init__.py
index 9dd7ada95..a3a3f5072 100644
--- a/electrum/gui/qt/qrreader/__init__.py
+++ b/electrum/gui/qt/qrreader/__init__.py
@@ -105,6 +105,9 @@ def _scan_qrcode_using_zbar(
     else:
         success = True
         error = ""
+    if data is None:
+        # probably user cancelled
+        success = False
     callback(success, error, data)
 
 
diff --git a/electrum/gui/qt/util.py b/electrum/gui/qt/util.py
index f24fa57a9..beb2d547f 100644
--- a/electrum/gui/qt/util.py
+++ b/electrum/gui/qt/util.py
@@ -672,7 +672,7 @@ class GenericInputHandler:
     ) -> None:
         if setText is None:
             setText = self.setText
-        def cb(success: bool, error: str, data):
+        def cb(success: bool, error: str, data: Optional[str]):
             if not success:
                 if error:
                     show_error(error)