diff --git a/reframe/frontend/cli.py b/reframe/frontend/cli.py
index e99f0e92c..c756338c8 100644
--- a/reframe/frontend/cli.py
+++ b/reframe/frontend/cli.py
@@ -1375,7 +1375,7 @@ def _case_failed(t):
             params = {}
             for param_spec in options.parameterize:
                 try:
-                    var, values_spec = param_spec.split('=')
+                    var, values_spec = param_spec.split('=', maxsplit=1)
                 except ValueError:
                     raise errors.CommandLineError(
                         f'invalid parameter spec: {param_spec}'
diff --git a/unittests/test_cli.py b/unittests/test_cli.py
index 50a8904df..a6cc007e0 100644
--- a/unittests/test_cli.py
+++ b/unittests/test_cli.py
@@ -1061,16 +1061,16 @@ def test_repeat_negative(run_reframe):
 
 def test_parameterize_tests(run_reframe):
     returncode, stdout, _ = run_reframe(
-        more_options=['-P', 'num_tasks=2,4,8', '-n', '^HelloTest'],
+        more_options=['-P', 'descr=msg=hello1,msg=hello2',
+                      '-n', '^HelloTest'],
         checkpath=['unittests/resources/checks/hellocheck.py'],
         action='describe'
     )
     assert returncode == 0
 
-    test_descr = json.loads(stdout)
-    print(json.dumps(test_descr, indent=2))
-    num_tasks = {t['num_tasks'] for t in test_descr}
-    assert num_tasks == {2, 4, 8}
+    test_json = json.loads(stdout)
+    descr = [t['descr'] for t in test_json]
+    assert descr == ['msg=hello1', 'msg=hello2']
 
 
 def test_parameterize_tests_invalid_params(run_reframe):