diff --git a/diesel/protocols/mongodb.py b/diesel/protocols/mongodb.py
index 12d6dd1..4be7e86 100644
--- a/diesel/protocols/mongodb.py
+++ b/diesel/protocols/mongodb.py
@@ -10,6 +10,8 @@
 _ZERO = "\x00\x00\x00\x00"
 HEADER_SIZE = 16
 
+class MongoOperationalError(Exception): pass
+
 def _full_name(parent, child):
     return "%s.%s" % (parent, child)
 
@@ -33,14 +35,14 @@ class Collection(TraversesCollections):
     def find(self, spec=None, fields=None, skip=0, limit=0):
         yield up(MongoCursor(self.name, self.client, spec, fields, skip, limit))
 
-    def update(self, spec, doc, upsert=False, multi=False):
-        yield self.client.update(self.name, spec, doc, upsert, multi)
+    def update(self, spec, doc, upsert=False, multi=False, safe=True):
+        yield self.client.update(self.name, spec, doc, upsert, multi, safe)
 
-    def insert(self, doc_or_docs):
-        yield self.client.insert(self.name, doc_or_docs)
+    def insert(self, doc_or_docs, safe=True):
+        yield self.client.insert(self.name, doc_or_docs, safe)
 
-    def delete(self, spec):
-        yield self.client.delete(self.name, spec)
+    def delete(self, spec, safe=True):
+        yield self.client.delete(self.name, spec, safe)
 
 class MongoClient(Client):
     collection_class = None
@@ -99,22 +101,36 @@ def get_more(self, cursor):
         else:
             yield response([])
 
+    def _put_gle_command(self):
+        msg = Ops.query('admin.$cmd', {'getlasterror' : 1}, 0, 0, -1)
+        res = yield self._put_request_get_response(Ops.OP_QUERY, msg)
+        _, _, _, r = res
+        doc = r[0]
+        if doc.get('err'):
+            raise MongoOperationalError(doc['error'])
+
     @call
-    def update(self, col, spec, doc, upsert=False, multi=False):
+    def update(self, col, spec, doc, upsert=False, multi=False, safe=True):
         data = Ops.update(col, spec, doc, upsert, multi)
         yield self._put_request(Ops.OP_UPDATE, data)
+        if safe:
+            yield self._put_gle_command()
         yield response(None)
 
     @call
-    def insert(self, col, doc_or_docs):
+    def insert(self, col, doc_or_docs, safe=True):
         data = Ops.insert(col, doc_or_docs)
         yield self._put_request(Ops.OP_INSERT, data)
+        if safe:
+            yield self._put_gle_command()
         yield response(None)
 
     @call
-    def delete(self, col, spec):
+    def delete(self, col, spec, safe=True):
         data = Ops.delete(col, spec)
         yield self._put_request(Ops.OP_DELETE, data)
+        if safe:
+            yield self._put_gle_command()
         yield response(None)
 
     @call