1 files changed, 5 insertions, 5 deletions
diff --git a/synapse/util/frozenutils.py b/synapse/util/frozenutils.py
index 15f0a7ba9e..014edea971 100644
--- a/synapse/util/frozenutils.py
+++ b/synapse/util/frozenutils.py
@@ -13,10 +13,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from frozendict import frozendict
-import simplejson as json
+from six import binary_type, text_type
 
-from six import string_types
+from canonicaljson import json
+from frozendict import frozendict
 
 
 def freeze(o):
@@ -26,7 +26,7 @@ def freeze(o):
     if isinstance(o, frozendict):
         return o
 
-    if isinstance(o, string_types):
+    if isinstance(o, (binary_type, text_type)):
         return o
 
     try:
@@ -41,7 +41,7 @@ def unfreeze(o):
     if isinstance(o, (dict, frozendict)):
         return dict({k: unfreeze(v) for k, v in o.items()})
 
-    if isinstance(o, string_types):
+    if isinstance(o, (binary_type, text_type)):
         return o
 
     try: