diff --git a/lower-constraints.txt b/lower-constraints.txt
index 1099048..d2cee79 100644
--- a/lower-constraints.txt
+++ b/lower-constraints.txt
@@ -28,7 +28,7 @@ openstackdocstheme==1.18.1
 os-client-config==1.28.0
 oslo.i18n==3.15.3
 oslo.log==3.36.0
-oslo.serialization==2.18.0
+oslo.serialization==2.21.1
 oslo.utils==3.33.0
 oslotest==3.2.0
 pbr==2.0.0
@@ -54,3 +54,4 @@ testtools==2.2.0
 traceback2==1.4.0
 unittest2==1.1.0
 wrapt==1.7.0
+yaql==1.1.3 # Apache 2.0 License
diff --git a/mistral_lib/tests/test_utils.py b/mistral_lib/tests/test_utils.py
index 23bdb3d..eeb754c 100644
--- a/mistral_lib/tests/test_utils.py
+++ b/mistral_lib/tests/test_utils.py
@@ -14,10 +14,14 @@
 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 # License for the specific language governing permissions and limitations
 # under the License.
+
 import copy
 
+from yaql.language import utils as yaql_utils
+
 from mistral_lib.tests import base as tests_base
 from mistral_lib import utils
+
 import testtools.matchers as ttm
 
 
@@ -267,3 +271,70 @@ class TestUtils(tests_base.TestCase):
         payload = ["adminPass", 'fooBarBaz']
         expected = ["adminPass", 'fooBarBaz']
         self.assertEqual(expected, utils.mask_data(payload))
+
+    def test_json_serialize_frozen_dict(self):
+        data = yaql_utils.FrozenDict(a=1, b=2, c=iter([1, 2, 3]))
+
+        json_str = utils.to_json_str(data)
+
+        self.assertIsNotNone(json_str)
+
+        self.assertIn('"a": 1', json_str)
+        self.assertIn('"b": 2', json_str)
+        self.assertIn('"c": [1, 2, 3]', json_str)
+
+    def test_json_serialize_generator(self):
+        def _list_stream(_list):
+            for i in _list:
+                yield i
+
+        gen = _list_stream(
+            [1, yaql_utils.FrozenDict(a=1), _list_stream([12, 15])]
+        )
+
+        self.assertEqual('[1, {"a": 1}, [12, 15]]', utils.to_json_str(gen))
+
+    def test_json_serialize_dict_of_generators(self):
+        def _f(cnt):
+            for i in range(1, cnt + 1):
+                yield i
+
+        data = {'numbers': _f(3)}
+
+        self.assertEqual('{"numbers": [1, 2, 3]}', utils.to_json_str(data))
+
+    def test_json_serialize_range(self):
+        self.assertEqual("[1, 2, 3, 4]", utils.to_json_str(range(1, 5)))
+
+    def test_json_serialize_iterator_of_frozen_dicts(self):
+        data = iter(
+            [
+                yaql_utils.FrozenDict(a=1, b=2, c=iter([1, 2, 3])),
+                yaql_utils.FrozenDict(
+                    a=11,
+                    b=yaql_utils.FrozenDict(b='222'),
+                    c=iter(
+                        [
+                            1,
+                            yaql_utils.FrozenDict(
+                                a=iter([4, yaql_utils.FrozenDict(a=99)])
+                            )
+                        ]
+                    )
+                )
+            ]
+        )
+
+        json_str = utils.to_json_str(data)
+
+        self.assertIsNotNone(json_str)
+
+        # Checking the first item.
+        self.assertIn('"a": 1', json_str)
+        self.assertIn('"b": 2', json_str)
+        self.assertIn('"c": [1, 2, 3]', json_str)
+
+        # Checking the first item.
+        self.assertIn('"a": 11', json_str)
+        self.assertIn('"b": {"b": "222"}', json_str)
+        self.assertIn('"c": [1, {"a": [4, {"a": 99}]}]', json_str)
diff --git a/mistral_lib/utils/__init__.py b/mistral_lib/utils/__init__.py
index 2d4e9c4..56f88b4 100644
--- a/mistral_lib/utils/__init__.py
+++ b/mistral_lib/utils/__init__.py
@@ -17,6 +17,7 @@
 
 import datetime
 import functools
+import inspect
 import json
 import os
 from os import path
@@ -28,6 +29,7 @@ import threading
 import eventlet
 from eventlet import corolocal
 from oslo_log import log as logging
+from oslo_serialization import jsonutils
 from oslo_utils.strutils import mask_dict_password
 from oslo_utils.strutils import mask_password
 from oslo_utils import timeutils
@@ -495,3 +497,52 @@ def mask_data(obj):
         return [mask_data(i) for i in obj]
     else:
         return mask_password(obj)
+
+
+def to_json_str(obj):
+    """Serializes an object into a JSON string.
+
+    :param obj: Object to serialize.
+    :return: JSON string.
+    """
+
+    if obj is None:
+        return None
+
+    def _fallback(value):
+        if inspect.isgenerator(value):
+            result = list(value)
+
+            # The result of the generator call may be again not primitive
+            # so we need to call "to_primitive" again with the same fallback
+            # function. Note that the endless recursion here is not a problem
+            # because "to_primitive" limits the depth for custom classes,
+            # if they are present in the object graph being traversed.
+            return jsonutils.to_primitive(
+                result,
+                convert_instances=True,
+                fallback=_fallback
+            )
+
+        return value
+
+    # We need to convert the root of the given object graph into
+    # a primitive by hand so that we also enable conversion of
+    # object of custom classes into primitives. Otherwise, they are
+    # ignored by the "json" lib.
+    return jsonutils.dumps(
+        jsonutils.to_primitive(obj, convert_instances=True, fallback=_fallback)
+    )
+
+
+def from_json_str(json_str):
+    """Reconstructs an object from a JSON string.
+
+    :param json_str: A JSON string.
+    :return: Deserialized object.
+    """
+
+    if json_str is None:
+        return None
+
+    return jsonutils.loads(json_str)
diff --git a/requirements.txt b/requirements.txt
index c9e2689..0b1c906 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,4 +5,5 @@
 eventlet!=0.20.1,>=0.20.0 # MIT
 oslo.log>=3.36.0 # Apache-2.0
 pbr!=2.1.0,>=2.0.0 # Apache-2.0
-oslo.serialization!=2.19.1,>=2.18.0 # Apache-2.0
+oslo.serialization>=2.21.1 # Apache-2.0
+yaql>=1.1.3 # Apache 2.0 License