diff --git a/flask_profiler/storage/mongo.py b/flask_profiler/storage/mongo.py
index d3571a5..0303c6c 100644
--- a/flask_profiler/storage/mongo.py
+++ b/flask_profiler/storage/mongo.py
@@ -20,7 +20,7 @@ def __init__(self, config=None):
         self.collection_name = self.config.get("COLLECTION", "measurements")
 
         def createIndex():
-            self.collection.ensure_index(
+            self.collection.create_index(
                 [
                     ('startedAt', 1),
                     ('endedAt', 1),
@@ -86,19 +86,19 @@ def insert(self, measurement):
         measurement["endedAt"] = datetime.datetime.fromtimestamp(
             measurement["endedAt"])
 
-        result = self.collection.insert(measurement)
+        result = self.collection.insert_one(measurement)
         if result:
             return True
         return False
 
     def truncate(self):
-        result = self.collection.remove()
+        result = self.collection.delete_many({})
         if result:
             return True
         return False
 
     def delete(self, measurementId):
-        result = self.collection.remove({"_id": ObjectId(measurementId)})
+        result = self.collection.delete_one({"_id": ObjectId(measurementId)})
         if result:
             return True
         return False
@@ -248,7 +248,7 @@ def clearify(self, obj):
         available_types = [int, dict, str, list]
         obj["startedAt"] = obj["startedAt"].strftime("%s")
         obj["endedAt"] = obj["endedAt"].strftime("%s")
-        for k, v in obj.items():
+        for k, v in list(obj.items()):
             if any([isinstance(v, av_type) for av_type in available_types]):
                 continue
             if k == "_id":