diff --git a/src/ansys/openapi/common/_api_client.py b/src/ansys/openapi/common/_api_client.py
index dccdd373..6d733d12 100644
--- a/src/ansys/openapi/common/_api_client.py
+++ b/src/ansys/openapi/common/_api_client.py
@@ -319,15 +319,12 @@ def deserialize(
         if response_type == "file":
             return self.__deserialize_file(response)
 
-        try:
-            data = response.json()
-        except ValueError:
-            content_type = response.headers.get(
-                "Content-Type", "application/octet-stream"
-            )
-            if content_type not in ["application/octet-stream"]:
-                data = response.text
-            else:
+        if response_type == "str":
+            data: SerializedType = response.text
+        else:
+            try:
+                data = response.json()
+            except ValueError:
                 data = response.content
 
         return self.__deserialize(data, response_type)
diff --git a/tests/test_api_client.py b/tests/test_api_client.py
index c4202f46..1c0d3b9f 100644
--- a/tests/test_api_client.py
+++ b/tests/test_api_client.py
@@ -378,9 +378,9 @@ def test_json_parsed_as_json(self, mocker):
         response = self.create_response(data)
         deserialize_mock = mocker.patch.object(ApiClient, "_ApiClient__deserialize")
         deserialize_mock.return_value = True
-        _ = self._client.deserialize(response, dict)
+        _ = self._client.deserialize(response, "dict")
         deserialize_mock.assert_called()
-        deserialize_mock.assert_called_once_with(data, dict)
+        deserialize_mock.assert_called_once_with(data, "dict")
 
     def test_text_parsed_as_text(self, mocker):
         data = "This is some data this is definitely not json, it should be rendered as a string"
@@ -391,6 +391,15 @@ def test_text_parsed_as_text(self, mocker):
         deserialize_mock.assert_called()
         deserialize_mock.assert_called_once_with(data, "str")
 
+    def test_deserialize_json_as_string_returns_string(self, mocker):
+        data = json.dumps({"foo": "bar", "baz": [1, 2, 3]})
+        response = self.create_response(text=data, content_type="text/plain")
+        deserialize_mock = mocker.patch.object(ApiClient, "_ApiClient__deserialize")
+        deserialize_mock.return_value = True
+        _ = self._client.deserialize(response, "str")
+        deserialize_mock.assert_called()
+        deserialize_mock.assert_called_once_with(data, "str")
+
     @pytest.mark.parametrize("provide_content_type", (True, False))
     def test_application_data_is_not_parsed(self, mocker, provide_content_type):
         # The false case tests the default handling of non-json data