diff --git a/lib/filters/equality_filter.js b/lib/filters/equality_filter.js
index 87b7931..9638507 100644
--- a/lib/filters/equality_filter.js
+++ b/lib/filters/equality_filter.js
@@ -49,10 +49,16 @@ EqualityFilter.prototype.matches = function (target) {
   if (typeof (target) !== 'object')
     throw new TypeError('target (object) required');
 
+  var self = this;
+
   if (target.hasOwnProperty(this.attribute)) {
     var value = this.value;
     return Filter.multi_test(
-      function (v) { return value === v; },
+      function (v) {
+        if (self.attribute === 'objectclass')
+          v = v.toLowerCase();
+        return value === v;
+      },
       target[this.attribute]);
   }
 
diff --git a/lib/filters/substr_filter.js b/lib/filters/substr_filter.js
index e3672d6..417a2cc 100644
--- a/lib/filters/substr_filter.js
+++ b/lib/filters/substr_filter.js
@@ -89,8 +89,13 @@ SubstringFilter.prototype.matches = function (target) {
       re += this['final'] + '$';
 
     var matcher = new RegExp(re);
+    var self = this;
     return Filter.multi_test(
-      function (v) { return matcher.test(v); },
+      function (v) {
+        if (self.attribute === 'objectclass')
+          v = v.toLowerCase();
+        return matcher.test(v);
+      },
       target[this.attribute]);
   }