diff --git a/src/js/datamaps.js b/src/js/datamaps.js
index 16b983c6..96be2399 100644
--- a/src/js/datamaps.js
+++ b/src/js/datamaps.js
@@ -1126,14 +1126,20 @@
         // If it's an object, overriding the previous data
         if ( subunitData === Object(subunitData) ) {
           this.options.data[subunit] = defaults(subunitData, this.options.data[subunit] || {});
-          var geo = this.svg.select('.' + subunit).attr('data-info', JSON.stringify(this.options.data[subunit]));
+          var geo = this.svg.select('.' + CSS.escape(subunit)).attr('data-info', JSON.stringify(this.options.data[subunit]));
         }
         svg
-          .selectAll('.' + subunit)
+          .selectAll('.' + CSS.escape(subunit))
           .transition()
             .style('fill', color);
       }
     }
+    
+    for (var existingSubunit in this.options.data) {
+      if(this.options.data.hasOwnProperty(existingSubunit) && !data.hasOwnProperty(existingSubunit)) {
+        map.options.data[existingSubunit] = {};
+      }
+    }
   };
 
   Datamap.prototype.updatePopup = function (element, d, options) {