diff --git a/MODULE.bazel b/MODULE.bazel
index e60e719..f14196e 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -27,7 +27,7 @@ git_override(
 bazel_dep(name = "cel-spec", version = "0.25.3", repo_name = "com_google_cel_spec")
 git_override(
     module_name = "cel-spec",
-    commit = "ba58ae5007845f3a1279b488cdeb79645ce958bb",
+    commit = "6dccde40b346f89761ddb890abc6ca503a453134",
     remote = "https://github.com/cel-expr/cel-spec",
 )
 
diff --git a/conformance/conformance_test.py b/conformance/conformance_test.py
index de54d1b..b41acdb 100644
--- a/conformance/conformance_test.py
+++ b/conformance/conformance_test.py
@@ -53,6 +53,10 @@ class ConformanceTestSuite(unittest.TestSuite):
       "type_deduction/type_parameters/multiple_parameters_parameterized_ovl",
       "type_deduction/type_parameters/multiple_parameters_parameterized_ovl_2",
       "type_deduction/flexible_type_parameter_assignment/unconstrained_type_var_as_dyn",
+      "type_deduction/type_parameters_in_type_type/type_param_in_type_type_int",
+      "type_deduction/type_parameters_in_type_type/type_param_in_type_type_string",
+      "type_deduction/type_parameters_in_type_type/composite_type_param_in_type_type",
+      "type_deduction/type_parameters_in_type_type/nested_type_param_in_type_type",
       # TODO(b/178627883): Strong typing support for enums not implemented.
       "enums/strong_proto2/.*",
       "enums/strong_proto3/.*",
@@ -74,6 +78,13 @@ class ConformanceTestSuite(unittest.TestSuite):
       "proto3/set_null/map_timestamp_null_pruned",
       "proto3/set_null/map_duration_null_pruned",
       "proto3/set_null/map_wrapper_null_pruned",
+      # TODO(b/577138668): C++ type checker bug, though lower priority.
+      "type_deduction/type_decay/type_list_decay",
+      "type_deduction/type_decay/type_ternary_decay",
+      "type_deduction/type_decay/type_free_param_list_decay",
+      "type_deduction/type_decay/type_free_param_list_decay_order_independent",
+      "type_deduction/type_decay/type_nested_list_decay",
+      "type_deduction/type_decay/type_free_param_list_concat",
   ]
 
   if sys.platform == "win32":