diff --git a/setup.py b/setup.py
index 5a6ecaf..34c4e84 100644
--- a/setup.py
+++ b/setup.py
@@ -14,7 +14,8 @@ setup(
     install_requires=[
         "Flask >= 1.1",
         "toml",
-        "sqlalchemy>=1.3",
+        # < 1.4: https://github.com/pallets/flask-sqlalchemy/issues/885
+        "sqlalchemy>=1.3,<1.4",
         "flask_sqlalchemy",
         "flask_cors",
         "werkzeug",