diff --git a/dist/leaflet.markercluster-src.js b/dist/leaflet.markercluster-src.js
index 2c4a3e632..0f02a59a9 100644
--- a/dist/leaflet.markercluster-src.js
+++ b/dist/leaflet.markercluster-src.js
@@ -190,7 +190,9 @@ L.MarkerClusterGroup = L.FeatureGroup.extend({
 		//If we aren't on the map yet, just blow away the markers we know of
 		if (!this._map) {
 			this._needsClustering = [];
-			return this;
+			this._gridClusters = undefined;
+			this._gridUnclustered = undefined;
+			// return this;
 		}
 
 		if (this._unspiderfy) {
@@ -204,8 +206,10 @@ L.MarkerClusterGroup = L.FeatureGroup.extend({
 			}
 		}
 
-		//Reset _topClusterLevel and the DistanceGrids
-		this._generateInitialClusters();
+		if (this._map) {
+			//Reset _topClusterLevel and the DistanceGrids
+			this._generateInitialClusters();
+		}
 
 		return this;
 	},
diff --git a/src/MarkerClusterGroup.js b/src/MarkerClusterGroup.js
index c4affab81..f92745dc1 100644
--- a/src/MarkerClusterGroup.js
+++ b/src/MarkerClusterGroup.js
@@ -183,7 +183,9 @@ L.MarkerClusterGroup = L.FeatureGroup.extend({
 		//If we aren't on the map yet, just blow away the markers we know of
 		if (!this._map) {
 			this._needsClustering = [];
-			return this;
+			this._gridClusters = undefined;
+			this._gridUnclustered = undefined;
+			// return this;
 		}
 
 		if (this._unspiderfy) {
@@ -197,8 +199,10 @@ L.MarkerClusterGroup = L.FeatureGroup.extend({
 			}
 		}
 
-		//Reset _topClusterLevel and the DistanceGrids
-		this._generateInitialClusters();
+		if (this._map) {
+			//Reset _topClusterLevel and the DistanceGrids
+			this._generateInitialClusters();
+		}
 
 		return this;
 	},