diff --git a/pkgs/development/python-modules/pecan/default.nix b/pkgs/development/python-modules/pecan/default.nix
index 40b9d437993b..c0954ec3ca31 100644
--- a/pkgs/development/python-modules/pecan/default.nix
+++ b/pkgs/development/python-modules/pecan/default.nix
@@ -44,6 +44,16 @@ buildPythonPackage rec {
 
   pytestFlagsArray = [
     "--pyargs pecan"
+    # tests fail with sqlalchemy 2.0
+  ] ++ lib.optionals (lib.versionAtLeast sqlalchemy.version "2.0") [
+    # The 'sqlalchemy.orm.mapper()' function is removed as of SQLAlchemy
+    # 2.0.  Use the 'sqlalchemy.orm.registry.map_imperatively()` method
+    # of the ``sqlalchemy.orm.registry`` class to perform classical
+    # mapping.
+    # https://github.com/pecan/pecan/issues/143
+    "--deselect=pecan/tests/test_jsonify.py::TestJsonifySQLAlchemyGenericEncoder::test_result_proxy"
+    "--deselect=pecan/tests/test_jsonify.py::TestJsonifySQLAlchemyGenericEncoder::test_row_proxy"
+    "--deselect=pecan/tests/test_jsonify.py::TestJsonifySQLAlchemyGenericEncoder::test_sa_object"
   ];
 
   pythonImportsCheck = [
@@ -51,7 +61,6 @@ buildPythonPackage rec {
   ];
 
   meta = with lib; {
-    broken = lib.versionAtLeast sqlalchemy.version "2.0";
     changelog = "https://pecan.readthedocs.io/en/latest/changes.html";
     description = "WSGI object-dispatching web framework";
     homepage = "https://www.pecanpy.org/";