diff --git a/db/clientcursor.h b/db/clientcursor.h
index 6f79dcff372..b895c1769ac 100644
--- a/db/clientcursor.h
+++ b/db/clientcursor.h
@@ -138,17 +138,18 @@ namespace mongo {
         /*const*/ CursorId cursorid;
         const string ns;
         const shared_ptr<Cursor> c;
-        int pos;                  // # objects into the cursor so far 
-        BSONObj query;
+        int pos;                        // # objects into the cursor so far 
+        const BSONObj query;            // used for logging diags only; optional in constructor
         const int _queryOptions;        // see enum QueryOptions dbclient.h
         OpTime _slaveReadTill;
         Database * const _db;
 
-        ClientCursor(int queryOptions, shared_ptr<Cursor>& _c, const string& _ns) :
+        ClientCursor(int queryOptions, shared_ptr<Cursor>& _c, const string& _ns, BSONObj _query = BSONObj()) :
             _idleAgeMillis(0), _pinValue(0), 
             _doingDeletes(false), _yieldSometimesTracker(128,10),
             ns(_ns), c(_c), 
-            pos(0), _queryOptions(queryOptions), 
+            pos(0), query(_query), 
+            _queryOptions(queryOptions), 
             _db( cc().database() )
         {
             assert( _db );
diff --git a/db/oplog.h b/db/oplog.h
index d1e49900dc9..34c345f31e0 100644
--- a/db/oplog.h
+++ b/db/oplog.h
@@ -195,7 +195,7 @@ namespace mongo {
             // Use a ClientCursor here so we can release db mutex while scanning
             // oplog (can take quite a while with large oplogs).
             shared_ptr<Cursor> c = _qp.newReverseCursor();
-            _findingStartCursor = new ClientCursor(QueryOption_NoCursorTimeout, c, _qp.ns());
+            _findingStartCursor = new ClientCursor(QueryOption_NoCursorTimeout, c, _qp.ns(), BSONObj());
             _findingStartTimer.reset();
             _findingStartMode = Initial;
             BSONElement tsElt = _qp.originalQuery()[ "ts" ];
diff --git a/db/query.cpp b/db/query.cpp
index 60b58998bc0..baf49df03d8 100644
--- a/db/query.cpp
+++ b/db/query.cpp
@@ -1063,13 +1063,12 @@ namespace mongo {
             if ( moreClauses ) {
                 // this MultiCursor will use a dumb NoOp to advance(), so no need to specify mayYield
                 shared_ptr< Cursor > multi( new MultiCursor( mps, cursor, dqo.matcher(), dqo ) );
-                cc = new ClientCursor(queryOptions, multi, ns);
+                cc = new ClientCursor(queryOptions, multi, ns, jsobj.getOwned());
             } else {
                 cursor->setMatcher( dqo.matcher() );
-                cc = new ClientCursor( queryOptions, cursor, ns );
+                cc = new ClientCursor( queryOptions, cursor, ns, jsobj.getOwned() );
             }
             cursorid = cc->cursorid;
-            cc->query = jsobj.getOwned();
             DEV tlog(2) << "query has more, cursorid: " << cursorid << endl;
             cc->pos = n;
             cc->pq = pq_shared;