diff --git a/db/btree.h b/db/btree.h
index c3327c04eae..0dbcb067a6d 100644
--- a/db/btree.h
+++ b/db/btree.h
@@ -385,6 +385,7 @@ namespace mongo {
         }
         
         virtual bool modifiedKeys() const { return _multikey; }
+        virtual bool isMultiKey() const { return _multikey; }
 
         const _KeyNode& _currKeyNode() const {
             assert( !bucket.isNull() );
diff --git a/db/cursor.h b/db/cursor.h
index bfad4fd6747..1b0d402c2d2 100644
--- a/db/cursor.h
+++ b/db/cursor.h
@@ -93,6 +93,8 @@ namespace mongo {
         */
         virtual bool getsetdup(DiskLoc loc) = 0;
         
+        virtual bool isMultiKey() const = 0;
+
         /**
          * return true if the keys in the index have been modified from the main doc
          * if you have { a : 1 , b : [ 1 , 2 ] } 
@@ -161,6 +163,7 @@ namespace mongo {
         }
         virtual bool tailable() { return tailable_; }
         virtual bool getsetdup(DiskLoc loc) { return false; }
+        virtual bool isMultiKey() const { return false; }
         virtual bool modifiedKeys() const { return false; }
         virtual bool supportGetMore() { return true; }
         virtual bool supportYields() { return true; }
diff --git a/db/geo/2d.cpp b/db/geo/2d.cpp
index 26574a2573c..6e9aac7c6ba 100644
--- a/db/geo/2d.cpp
+++ b/db/geo/2d.cpp
@@ -1066,6 +1066,7 @@ namespace mongo {
         
         virtual bool getsetdup(DiskLoc loc) { return false; }
         virtual bool modifiedKeys() const { return true; }
+        virtual bool isMultiKey() const { return false; }
 
         
 
diff --git a/db/query.cpp b/db/query.cpp
index 0f96ef57321..7de5aa4f089 100644
--- a/db/query.cpp
+++ b/db/query.cpp
@@ -569,6 +569,7 @@ namespace mongo {
             
             *_b << "nYields" << nYields;
             *_b << "nChunkSkips" << nChunkSkips;
+            *_b << "isMultiKey" << c->isMultiKey();
 
             *_b << "indexBounds" << c->prettyIndexBounds();
 
diff --git a/db/queryoptimizer.cpp b/db/queryoptimizer.cpp
index 5c9953a4334..ce5d660f98b 100644
--- a/db/queryoptimizer.cpp
+++ b/db/queryoptimizer.cpp
@@ -273,6 +273,14 @@ namespace mongo {
         return false;
     }
 
+    bool QueryPlanSet::hasMultiKey() const {
+        for( PlanSet::const_iterator i = _plans.begin(); i != _plans.end(); ++i )
+            if ( (*i)->isMultiKey() )
+                return true;
+        return false;
+    }
+
+
     void QueryPlanSet::addHint( IndexDetails &id ) {
         if ( !_min.isEmpty() || !_max.isEmpty() ) {
             string errmsg;
diff --git a/db/queryoptimizer.h b/db/queryoptimizer.h
index 13be9edf947..fb92e00933f 100644
--- a/db/queryoptimizer.h
+++ b/db/queryoptimizer.h
@@ -206,6 +206,7 @@ namespace mongo {
         const FieldRangeSet &fbs() const { return *_fbs; }
         const FieldRangeSet &originalFrs() const { return *_originalFrs; }
         bool modifiedKeys() const;
+        bool hasMultiKey() const;
 
     private:
         void addOtherPlans( bool checkFirst );
@@ -300,6 +301,8 @@ namespace mongo {
         void setBestGuessOnly() { _bestGuessOnly = true; }
         void mayYield( bool val ) { _mayYield = val; }
         bool modifiedKeys() const { return _currentQps->modifiedKeys(); }
+        bool hasMultiKey() const { return _currentQps->hasMultiKey(); }
+
     private:
         void assertNotOr() const {
             massert( 13266, "not implemented for $or query", !_or );
@@ -384,6 +387,8 @@ namespace mongo {
         
         virtual bool modifiedKeys() const { return _mps->modifiedKeys(); }
         
+        virtual bool isMultiKey() const { return _mps->hasMultiKey(); }
+
         virtual CoveredIndexMatcher *matcher() const { return _matcher.get(); }
         // return -1 if we're a getmore handoff
         virtual long long nscanned() { return _nscanned >= 0 ? _nscanned + _c->nscanned() : _nscanned; }