diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index ceceaa0a..24eafbb2 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -8,6 +8,7 @@ Current
 
 - Ensure that exceptions raised in error handler, including programming errors, are logged (:issue:`705`, :pr:`706`)
 - Import the ABCs from 'collections.abc' instead of 'collections' by default as it is deprecated since Python3.7, and in 3.8 it will stop working. Python2.7 is still supported though.
+- Fix illegal characters in JSON references to model names (:issue:`651`)
 
 0.13.0 (2019-08-12)
 -------------------
@@ -20,6 +21,7 @@ Current
 - Per route Swagger documentation for multiple routes on a ``Resource``
 - Fix Swagger `duplicate mapping key` problem from conflicts between response codes given as string or integer (:issue`661`)
 
+
 0.12.1 (2018-09-28)
 -------------------
 
diff --git a/flask_restplus/swagger.py b/flask_restplus/swagger.py
index 64511ef0..2c61af3d 100644
--- a/flask_restplus/swagger.py
+++ b/flask_restplus/swagger.py
@@ -21,6 +21,10 @@
 from .utils import merge, not_none, not_none_sorted
 from ._http import HTTPStatus
 
+try:
+    from urllib.parse import quote
+except ImportError:
+    from urllib import quote
 
 #: Maps Flask/Werkzeug rooting types to Swagger ones
 PATH_TYPES = {
@@ -51,7 +55,7 @@
 def ref(model):
     '''Return a reference to model in definitions'''
     name = model.name if isinstance(model, ModelBase) else model
-    return {'$ref': '#/definitions/{0}'.format(name)}
+    return {'$ref': '#/definitions/{0}'.format(quote(name, safe=''))}
 
 
 def _v(value):
diff --git a/tests/test_swagger.py b/tests/test_swagger.py
index 9e583f55..d781334b 100644
--- a/tests/test_swagger.py
+++ b/tests/test_swagger.py
@@ -1669,6 +1669,33 @@ def get(self):
             }
         }
 
+    def test_model_with_non_uri_chars_in_name(self, api, client):
+        # name will be encoded as 'Person%2F%2F%3Flots%7B%7D%20of%20%26illegals%40%60'
+        name = 'Person//?lots{} of &illegals@`'
+        fields = api.model(name, {
+        })
+
+        @api.route('/model-bad-uri/')
+        class ModelBadUri(restplus.Resource):
+            @api.doc(model=fields)
+            def get(self):
+                return {}
+
+            @api.response(201, "", model=name)
+            def post(self):
+                return {}
+
+        data = client.get_specs()
+
+        assert 'definitions' in data
+        assert name in data['definitions']
+
+        path = data['paths']['/model-bad-uri/']
+        assert path['get']['responses']['200']['schema']['$ref'] == \
+            '#/definitions/Person%2F%2F%3Flots%7B%7D%20of%20%26illegals%40%60'
+        assert path['post']['responses']['201']['schema']['$ref'] == \
+            '#/definitions/Person%2F%2F%3Flots%7B%7D%20of%20%26illegals%40%60'
+
     def test_marchal_decorator_with_code(self, api, client):
         fields = api.model('Person', {
             'name': restplus.fields.String,