diff --git a/setup.py b/setup.py
index d65355b..c52b0be 100644
--- a/setup.py
+++ b/setup.py
@@ -35,7 +35,7 @@ def find_version(*file_paths):
       long_description=long_description,
       install_requires=[
           'flask>=2,<4',
-          'pyee>=8',
+          'pyee>=8,<12',
       ],
       classifiers=[
           'Development Status :: 5 - Production/Stable',