diff --git a/connexion/operations/openapi.py b/connexion/operations/openapi.py
index 7f5d0de3a..176eb9669 100644
--- a/connexion/operations/openapi.py
+++ b/connexion/operations/openapi.py
@@ -9,6 +9,7 @@
 from connexion.operations.abstract import AbstractOperation
 
 from ..decorators.uri_parsing import OpenAPIURIParser
+from ..http_facts import FORM_CONTENT_TYPES
 from ..utils import deep_get, deep_merge, is_null, is_nullable, make_type
 
 logger = logging.getLogger("connexion.operations.openapi3")
@@ -286,13 +287,28 @@ def _get_body_argument(self, body, arguments, has_kwargs, sanitize):
                           'the requestBody instead.', DeprecationWarning)
             x_body_name = sanitize(self.body_schema.get('x-body-name', 'body'))
 
+        if self.consumes[0] in FORM_CONTENT_TYPES:
+            result = self._get_body_argument_form(body)
+        else:
+            result = self._get_body_argument_json(body)
+
+        if x_body_name in arguments or has_kwargs:
+            return {x_body_name: result}
+        return {}
+
+    def _get_body_argument_json(self, body):
         # if the body came in null, and the schema says it can be null, we decide
         # to include no value for the body argument, rather than the default body
         if is_nullable(self.body_schema) and is_null(body):
-            if x_body_name in arguments or has_kwargs:
-                return {x_body_name: None}
-            return {}
+            return None
+
+        if body is None:
+            default_body = self.body_schema.get('default', {})
+            return deepcopy(default_body)
 
+        return body
+
+    def _get_body_argument_form(self, body):
         # now determine the actual value for the body (whether it came in or is default)
         default_body = self.body_schema.get('default', {})
         body_props = {k: {"schema": v} for k, v
@@ -302,25 +318,11 @@ def _get_body_argument(self, body, arguments, has_kwargs, sanitize):
         # see: https://github.com/OAI/OpenAPI-Specification/blame/3.0.2/versions/3.0.2.md#L2305
         additional_props = self.body_schema.get("additionalProperties", True)
 
-        if body is None:
-            body = deepcopy(default_body)
-
-        # if the body isn't even an object, then none of the concerns below matter
-        if self.body_schema.get("type") != "object":
-            if x_body_name in arguments or has_kwargs:
-                return {x_body_name: body}
-            return {}
-
-        # supply the initial defaults and convert all values to the proper types by schema
         body_arg = deepcopy(default_body)
         body_arg.update(body or {})
 
-        res = {}
         if body_props or additional_props:
-            res = self._get_typed_body_values(body_arg, body_props, additional_props)
-
-        if x_body_name in arguments or has_kwargs:
-            return {x_body_name: res}
+            return self._get_typed_body_values(body_arg, body_props, additional_props)
         return {}
 
     def _get_typed_body_values(self, body_arg, body_props, additional_props):
diff --git a/tests/api/test_responses.py b/tests/api/test_responses.py
index e5a6f38be..da76bbfba 100644
--- a/tests/api/test_responses.py
+++ b/tests/api/test_responses.py
@@ -388,3 +388,34 @@ def test_streaming_response(simple_app):
     app_client = simple_app.app.test_client()
     resp = app_client.get('/v1.0/get_streaming_response')
     assert resp.status_code == 200
+
+
+def test_oneof(simple_openapi_app):
+    app_client = simple_openapi_app.app.test_client()
+
+    post_greeting = app_client.post(  # type: flask.Response
+        '/v1.0/oneof_greeting',
+        data=json.dumps({"name": 3}),
+        content_type="application/json"
+    )
+    assert post_greeting.status_code == 200
+    assert post_greeting.content_type == 'application/json'
+    greeting_reponse = json.loads(post_greeting.data.decode('utf-8', 'replace'))
+    assert greeting_reponse['greeting'] == 'Hello 3'
+
+    post_greeting = app_client.post(  # type: flask.Response
+        '/v1.0/oneof_greeting',
+        data=json.dumps({"name": True}),
+        content_type="application/json"
+    )
+    assert post_greeting.status_code == 200
+    assert post_greeting.content_type == 'application/json'
+    greeting_reponse = json.loads(post_greeting.data.decode('utf-8', 'replace'))
+    assert greeting_reponse['greeting'] == 'Hello True'
+
+    post_greeting = app_client.post(  # type: flask.Response
+        '/v1.0/oneof_greeting',
+        data=json.dumps({"name": "jsantos"}),
+        content_type="application/json"
+    )
+    assert post_greeting.status_code == 400
diff --git a/tests/fixtures/simple/openapi.yaml b/tests/fixtures/simple/openapi.yaml
index 749abcb3f..9ab6f6915 100644
--- a/tests/fixtures/simple/openapi.yaml
+++ b/tests/fixtures/simple/openapi.yaml
@@ -1222,6 +1222,23 @@ paths:
               schema:
                 type: string
                 format: binary
+  /oneof_greeting:
+    post:
+      operationId: fakeapi.hello.post_greeting3
+      requestBody:
+        content:
+          application/json:
+            schema:
+              type: object
+              properties:
+                name:
+                  oneOf:
+                    - {type: boolean}
+                    - {type: number}
+              additionalProperties: false
+      responses:
+        '200':
+          description: Echo the validated request.
 
 servers:
   - url: http://localhost:{port}/{basePath}