diff --git a/src/Ardent/Ardent.php b/src/Ardent/Ardent.php
index 4659181..e15e508 100755
--- a/src/Ardent/Ardent.php
+++ b/src/Ardent/Ardent.php
@@ -821,39 +821,43 @@ protected function buildUniqueExclusionRules(array $rules = array()) {
             $ruleset = (is_string($ruleset))? explode('|', $ruleset) : $ruleset;
 
             foreach ($ruleset as &$rule) {
-              if (strpos($rule, 'unique:') === 0) {
-                // Stop splitting at 4 so final param will hold optional where clause
-                $params = explode(',', $rule, 4); 
-
-                $uniqueRules = array();
-                
-                // Append table name if needed
-                $table = explode(':', $params[0]);
-                if (count($table) == 1)
-                  $uniqueRules[1] = $this->getTable();
-                else
-                  $uniqueRules[1] = $table[1];
-               
-                // Append field name if needed
-                if (count($params) == 1)
-                  $uniqueRules[2] = $field;
-                else
-                  $uniqueRules[2] = $params[1];
-
-                if (isset($this->primaryKey)) {
-                  $uniqueRules[3] = $this->{$this->primaryKey};
-                  
-                  // If optional where rules are passed, append them otherwise use primary key
-                  $uniqueRules[4] = isset($params[3]) ? $params[3] : $this->primaryKey;
-                }
-                else {
-                  $uniqueRules[3] = $this->id;
+                if (strpos($rule, 'unique:') === 0) {
+                    // Stop splitting at 4 so final param will hold optional where clause
+                    $params = explode(',', $rule, 4);
+
+                    $uniqueRules = array();
+
+                    // Append table name if needed
+                    $table = explode(':', $params[0]);
+                    if (count($table) == 1) {
+                        $uniqueRules[1] = $this->getTable();
+                    } else {
+                        $uniqueRules[1] = $table[1];
+                    }
+
+                    // Append field name if needed
+                    if (count($params) == 1) {
+                        $uniqueRules[2] = $field;
+                    } else {
+                        $uniqueRules[2] = $params[1];
+                    }
+
+                    if (isset($this->primaryKey)) {
+                        if (isset($this->{$this->primaryKey})) {
+                            $uniqueRules[3] = $this->{$this->primaryKey};
+
+                            // If optional where rules are passed, append them otherwise use primary key
+                            $uniqueRules[4] = isset($params[3])? $params[3] : $this->primaryKey;
+                        }
+                    } else {
+                        if (isset($this->id)) {
+                            $uniqueRules[3] = $this->id;
+                        }
+                    }
+
+                    $rule = 'unique:'.implode(',', $uniqueRules);
                 }
-       
-                $rule = 'unique:' . implode(',', $uniqueRules);  
-              } // end if strpos unique
-              
-            } // end foreach ruleset
+            }
         }
         
         return $rules;