diff --git a/WORKSPACE b/WORKSPACE
index 53664717..e2bc9580 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -119,7 +119,7 @@ go_repository(
 # CEL Spec deps
 go_repository(
     name = "com_google_cel_spec",
-    commit = "910da5b5d08378a9a1f3ea3ba1979e16e6c6dbc1", # v 0.14.0
+    commit = "1bc3fb168317fa77d1227c52d0becbf2d358c023",
     importpath = "github.com/google/cel-spec",
 )
 
diff --git a/conformance/BUILD.bazel b/conformance/BUILD.bazel
index a89771a9..dc78a024 100644
--- a/conformance/BUILD.bazel
+++ b/conformance/BUILD.bazel
@@ -11,6 +11,7 @@ ALL_TESTS = [
     "@com_google_cel_spec//tests/simple:testdata/logic.textproto",
     "@com_google_cel_spec//tests/simple:testdata/macros.textproto",
     "@com_google_cel_spec//tests/simple:testdata/namespace.textproto",
+    "@com_google_cel_spec//tests/simple:testdata/optionals.textproto",
     "@com_google_cel_spec//tests/simple:testdata/parse.textproto",
     "@com_google_cel_spec//tests/simple:testdata/plumbing.textproto",
     "@com_google_cel_spec//tests/simple:testdata/proto2.textproto",