diff --git a/setup.py b/setup.py
index 63ce1795748..c1fc9e3662f 100644
--- a/setup.py
+++ b/setup.py
@@ -48,6 +48,7 @@
             'matplotlib',
             'Pillow',
             'fastapi',
+            'pydantic>=1.9.0',
             'uvicorn',
         ],
         'full': [
@@ -63,6 +64,7 @@
             'scipy',
             'av',
             'fastapi',
+            'pydantic>=1.9.0',
             'uvicorn',
             'strawberry-graphql',
         ],
diff --git a/tests/unit/test_pydantic.py b/tests/unit/test_pydantic.py
index 9ff6c8b052a..da67954efe5 100644
--- a/tests/unit/test_pydantic.py
+++ b/tests/unit/test_pydantic.py
@@ -159,6 +159,22 @@ def test_tags_int_float_str_bool(tag_type, tag_value, protocol):
     assert isinstance(dd, tag_type)
 
 
+@pytest.mark.parametrize('protocol', ['protobuf', 'jsonschema'])
+def test_infinity_no_coercion(protocol):
+    # Test for issue #948: https://github.com/docarray/docarray/issues/948
+    d = Document()
+    d.tags['title'] = 'Infinity'
+
+    d_pydantic = d.to_pydantic_model()
+    d_pydantic.tags['title'] = 'Infinity'
+
+    d_json = d.to_json(protocol=protocol)
+    assert '"title": "Infinity"' in d_json
+
+    d_dict = d.to_dict(protocol=protocol)
+    assert d_dict['tags']['title'] == 'Infinity'
+
+
 @pytest.mark.parametrize(
     'blob', [None, b'123', bytes(Document()), bytes(bytearray(os.urandom(512 * 4)))]
 )