diff --git a/.coveragerc b/.coveragerc
index d3d9b3a..9ba0ad9 100644
--- a/.coveragerc
+++ b/.coveragerc
@@ -3,3 +3,4 @@ omit =
     */site-packages/*
     */distutils/*
     tests/*
+    .tox/*
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e36479a..aced653 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -19,3 +19,5 @@ jobs:
               run: pip install -r requirements/test.txt
             - name: Run Tox
               run: tox -e py
+            - name: Upload Coverage to codecov
+              run: bash <(curl -s https://codecov.io/bash)
diff --git a/imagekitio/file.py b/imagekitio/file.py
index e7ee6ce..a18f1bb 100644
--- a/imagekitio/file.py
+++ b/imagekitio/file.py
@@ -1,4 +1,4 @@
-import json
+from json import dumps
 from typing import Any, Dict
 
 from .constants.errors import ERRORS
@@ -10,6 +10,10 @@
     snake_to_lower_camel,
 )
 
+try:
+    from simplejson.errors import JSONDecodeError
+except ImportError:
+    from json import JSONDecodeError
 
 class File(object):
     def __init__(self, request_obj):
@@ -47,7 +51,10 @@ def upload(self, file, file_name, options) -> Dict:
         )
 
         if resp.status_code > 200:
-            error = resp.json()
+            try:
+                error = resp.json()
+            except JSONDecodeError:
+                error = resp.text
             response = None
         else:
             error = None
@@ -107,7 +114,7 @@ def update_file_details(self, file_id: str, options: dict):
         url = "{}/{}/details/".format(URL.BASE_URL.value, file_id)
         headers = {"Content-Type": "application/json"}
         headers.update(self.request.get_auth_headers())
-        data = json.dumps(request_formatter(options))
+        data = dumps(request_formatter(options))
         resp = self.request.request(method="Patch", url=url, headers=headers, data=data)
         if resp.status_code > 200:
             error = resp.json()
@@ -171,7 +178,7 @@ def purge_cache(self, file_url: str = None) -> Dict[str, Any]:
         headers.update(self.request.get_auth_headers())
         body = {"url": file_url}
         resp = self.request.request(
-            "Post", headers=headers, url=url, data=json.dumps(body)
+            "Post", headers=headers, url=url, data=dumps(body)
         )
         formatted_resp = camel_dict_to_snake_dict(resp.json())
         if resp.status_code > 204:
diff --git a/tests/helpers.py b/tests/helpers.py
index e5d3e00..59e7ed4 100644
--- a/tests/helpers.py
+++ b/tests/helpers.py
@@ -6,6 +6,10 @@
 
 from imagekitio.client import ImageKit
 from tests.dummy_data.file import AUTHENTICATION_ERR_MSG, SUCCESS_GENERIC_RESP
+try:
+    from simplejson.errors import JSONDecodeError
+except ImportError:
+    from json import JSONDecodeError
 
 
 class ClientTestCase(unittest.TestCase):
@@ -41,6 +45,16 @@ def get_mocked_failed_resp(message=None, status=401):
     return mocked_resp
 
 
+def get_mocked_failed_resp_text():
+    """GET failed mocked response returned as text not json
+    """
+    mocked_resp = Mock(spec=Response)
+    mocked_resp.status_code = 502
+    mocked_resp.text = 'Bad Gateway'
+    mocked_resp.json.side_effect = JSONDecodeError("Expecting value: ", "Bad Gateway", 0)
+    return mocked_resp
+
+
 def get_mocked_success_resp(message: dict = None, status: int = 200):
     """GET success mocked response customize by parameter
     """
diff --git a/tests/test_files_ops.py b/tests/test_files_ops.py
index 47399a2..02f0a55 100644
--- a/tests/test_files_ops.py
+++ b/tests/test_files_ops.py
@@ -15,6 +15,7 @@
 from tests.helpers import (
     ClientTestCase,
     get_mocked_failed_resp,
+    get_mocked_failed_resp_text,
     get_mocked_success_resp,
 )
 from imagekitio.utils.formatter import request_formatter
@@ -173,6 +174,27 @@ def test_upload_file_fails_without_file_or_file_name(self) -> None:
         self.assertRaises(TypeError, self.client.upload_file, file_name=self.filename)
         self.assertRaises(TypeError, self.client.upload_file, file=self.image)
 
+    def test_upload_file_fails_without_json_response_from_server(self) -> None:
+        """Test upload raises error on non json response
+        """
+        self.client.ik_request.request = MagicMock(
+            return_value=get_mocked_failed_resp_text()
+        )
+        resp = self.client.upload(
+            file=self.image,
+            file_name="fileabc",
+            options={
+                "is_private_file": True,
+                "tags": ["abc"],
+                "response_fields": ["is_private_file", "tags"],
+                "custom_coordinates": "10,10,100,100",
+                "use_unique_file_name": True,
+                "folder": "abc"
+            }
+        )
+        self.assertIsNotNone(resp["error"])
+        self.assertIsNone(resp["response"])
+
 
 class TestListFiles(ClientTestCase):
     """
diff --git a/tox.ini b/tox.ini
index d58b7c5..ec49579 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,4 +5,6 @@ skipsdist = True
 [testenv]
 passenv = *
 deps = -rrequirements/test.txt
-commands = python -m unittest discover tests
+commands =
+  coverage run --append -m unittest discover tests
+  coverage report
\ No newline at end of file