diff --git a/cel_expr_python/BUILD b/cel_expr_python/BUILD
index 3329794..a76568d 100644
--- a/cel_expr_python/BUILD
+++ b/cel_expr_python/BUILD
@@ -146,11 +146,13 @@ py_test(
         ":cel",
     ],
     deps = [
-        ":cel",
         "//testing:proto2_test_all_types_py_pb2",
         "@com_google_absl_py//absl/testing:absltest",
         "@com_google_protobuf//:protobuf",
-    ],
+    ] + select({
+        "@platforms//os:windows": [],
+        "//conditions:default": [":cel"],
+    }),
 )
 
 py_test(
@@ -164,12 +166,16 @@ py_test(
         "//cel_expr_python/ext:ext_strings",
     ],
     deps = [
-        ":cel",
-        "//cel_expr_python/ext:ext_bindings",
-        "//cel_expr_python/ext:ext_math",
-        "//cel_expr_python/ext:ext_optional",
-        "//cel_expr_python/ext:ext_strings",
         "//testing:proto2_test_all_types_py_pb2",
         "@com_google_absl_py//absl/testing:absltest",
-    ],
+    ] + select({
+        "@platforms//os:windows": [],
+        "//conditions:default": [
+            ":cel",
+            "//cel_expr_python/ext:ext_bindings",
+            "//cel_expr_python/ext:ext_math",
+            "//cel_expr_python/ext:ext_optional",
+            "//cel_expr_python/ext:ext_strings",
+        ],
+    }),
 )
diff --git a/conformance/BUILD b/conformance/BUILD
index bd5480e..79bb661 100644
--- a/conformance/BUILD
+++ b/conformance/BUILD
@@ -48,22 +48,24 @@ py_test(
         "TEST_FILES": ",".join(["$(rlocationpath %s)" % t for t in _ALL_TESTS]),
     },
     deps = [
-        "@com_google_cel_spec//proto/cel/expr:checked_py_pb2",
-        "@com_google_cel_spec//proto/cel/expr:value_py_pb2",
-        "@com_google_absl_py//absl/testing:absltest",
-        "//cel_expr_python/ext:ext_bindings",
-        "//cel_expr_python/ext:ext_encoders",
-        "//cel_expr_python/ext:ext_math",
-        "//cel_expr_python/ext:ext_optional",
-        "//cel_expr_python/ext:ext_proto",
-        "//cel_expr_python/ext:ext_strings",
-        "//cel_expr_python:cel",
         "//testing:proto2_test_all_types_py_pb2",
         "//testing:proto3_test_all_types_py_pb2",
         "//testing:simple_py_pb2",
+        "@com_google_absl_py//absl/testing:absltest",
+        "@com_google_cel_spec//proto/cel/expr:checked_py_pb2",
+        "@com_google_cel_spec//proto/cel/expr:value_py_pb2",
         "@com_google_protobuf//:protobuf_python",
         "@rules_python//python/runfiles",
-
-        #        "//third_party/py/google/protobuf:use_fast_cpp_protos",  # Automatically added go/proto_python_upb_flip
-    ],
+    ] + select({
+        "@platforms//os:windows": [],
+        "//conditions:default": [
+            "//cel_expr_python:cel",
+            "//cel_expr_python/ext:ext_bindings",
+            "//cel_expr_python/ext:ext_encoders",
+            "//cel_expr_python/ext:ext_math",
+            "//cel_expr_python/ext:ext_optional",
+            "//cel_expr_python/ext:ext_proto",
+            "//cel_expr_python/ext:ext_strings",
+        ],
+    }),
 )
diff --git a/custom_ext/BUILD b/custom_ext/BUILD
index f1c7c05..1718513 100644
--- a/custom_ext/BUILD
+++ b/custom_ext/BUILD
@@ -47,11 +47,15 @@ py_test(
         "//cel_expr_python:cel",
     ],
     deps = [
-        ":sample_cel_ext_cc",
         ":sample_cel_ext_py",
-        "//cel_expr_python:cel",
         "@com_google_absl_py//absl/testing:absltest",
         "@com_google_absl_py//absl/testing:parameterized",
         "@com_google_protobuf//:protobuf_python",
-    ],
+    ] + select({
+        "@platforms//os:windows": [],
+        "//conditions:default": [
+            ":sample_cel_ext_cc",
+            "//cel_expr_python:cel",
+        ],
+    }),
 )