diff --git a/betterproto/tests/inputs/oneof/oneof-name.json b/betterproto/tests/inputs/oneof/oneof-name.json
index bde99de..45960e7 100644
--- a/betterproto/tests/inputs/oneof/oneof-name.json
+++ b/betterproto/tests/inputs/oneof/oneof-name.json
@@ -1,3 +1,3 @@
 {
-  "name": "foo"
+  "name": "foobar"
 }
diff --git a/betterproto/tests/inputs/oneof/oneof.json b/betterproto/tests/inputs/oneof/oneof.json
index 400decb..0197c99 100644
--- a/betterproto/tests/inputs/oneof/oneof.json
+++ b/betterproto/tests/inputs/oneof/oneof.json
@@ -1,3 +1,3 @@
 {
-  "count": 1
+  "count": 100
 }
diff --git a/betterproto/tests/inputs/oneof/test_oneof.py b/betterproto/tests/inputs/oneof/test_oneof.py
new file mode 100644
index 0000000..400e4fd
--- /dev/null
+++ b/betterproto/tests/inputs/oneof/test_oneof.py
@@ -0,0 +1,15 @@
+import betterproto
+from betterproto.tests.output_betterproto.oneof.oneof import Test
+from betterproto.tests.util import get_test_case_json_data
+
+
+def test_which_count():
+    message = Test()
+    message.from_json(get_test_case_json_data("oneof"))
+    assert betterproto.which_one_of(message, "foo") == ("count", 100)
+
+
+def test_which_name():
+    message = Test()
+    message.from_json(get_test_case_json_data("oneof", "oneof-name.json"))
+    assert betterproto.which_one_of(message, "foo") == ("name", "foobar")