diff --git a/scripts/pyqt5_to_pyqt6/pyqt5_to_pyqt6.py b/scripts/pyqt5_to_pyqt6/pyqt5_to_pyqt6.py
index da4f07c2c7b6..e238b550a4b6 100755
--- a/scripts/pyqt5_to_pyqt6/pyqt5_to_pyqt6.py
+++ b/scripts/pyqt5_to_pyqt6/pyqt5_to_pyqt6.py
@@ -50,6 +50,13 @@
 from collections.abc import Sequence
 from enum import Enum
 
+try:
+    import PyQt5
+
+    print("WARNING: PyQt5 has been found. It may result in wrong behavior.\n")
+except ImportError:
+    pass
+
 from PyQt6 import (
     Qsci,
     QtCore,