diff --git a/lib/Doctrine/Expression/Driver.php b/lib/Doctrine/Expression/Driver.php
index 8aa175e36..591c61775 100644
--- a/lib/Doctrine/Expression/Driver.php
+++ b/lib/Doctrine/Expression/Driver.php
@@ -299,15 +299,16 @@ class Doctrine_Expression_Driver extends Doctrine_Connection_Module
      * Returns a series of strings concatinated
      *
      * concat() accepts an arbitrary number of parameters. Each parameter
-     * must contain an expression or an array with expressions.
+     * must contain an expression
      *
-     * @param string|array(string) strings that will be concatinated.
+     * @param string $arg1, $arg2 ... $argN     strings that will be concatinated.
+     * @return string
      */
     public function concat()
     {
         $args = func_get_args();
 
-        return 'CONCAT(' . join(', ', (array) $args) . ')';
+        return join(' || ' , $args);
     }
 
     /**
@@ -717,7 +718,7 @@ class Doctrine_Expression_Driver extends Doctrine_Connection_Module
     /**
      * sin
      *
-     * @param string $value 
+     * @param string $value
      * @return void
      */
     public function sin($value)
@@ -738,7 +739,7 @@ class Doctrine_Expression_Driver extends Doctrine_Connection_Module
     /**
      * cos
      *
-     * @param string $value 
+     * @param string $value
      * @return void
      * @author Jonathan H. Wage
      */
@@ -752,11 +753,11 @@ class Doctrine_Expression_Driver extends Doctrine_Connection_Module
      *
      * for all native RDBMS functions the function name itself is returned
      */
-    public function __call($m, $a) 
+    public function __call($m, $a)
     {
         if ($this->conn->getAttribute(Doctrine::ATTR_PORTABILITY) & Doctrine::PORTABILITY_EXPR) {
             throw new Doctrine_Expression_Exception('Unknown expression ' . $m);
         }
         return $m . '(' . implode(', ', $a) . ')';
     }
-}
\ No newline at end of file
+}
diff --git a/lib/Doctrine/Expression/Mysql.php b/lib/Doctrine/Expression/Mysql.php
index 0f26b2057..bf9bb8afe 100644
--- a/lib/Doctrine/Expression/Mysql.php
+++ b/lib/Doctrine/Expression/Mysql.php
@@ -112,16 +112,17 @@ class Doctrine_Expression_Mysql extends Doctrine_Expression_Driver
     }
 
     /**
-     * Returns string to concatenate two or more string parameters
+     * Returns a series of strings concatinated
      *
-     * @param string $value1
-     * @param string $value2
-     * @param string $values...
-     * @return string to concatenate two strings
-     **/
-    function concat($value1, $value2)
+     * concat() accepts an arbitrary number of parameters. Each parameter
+     * must contain an expression or an array with expressions.
+     *
+     * @param string|array(string) strings that will be concatinated.
+     */
+    public function concat()
     {
         $args = func_get_args();
-        return 'CONCAT('.implode(', ', $args).')';
+
+        return 'CONCAT(' . join(', ', (array) $args) . ')';
     }
 }
diff --git a/lib/Doctrine/Expression/Oracle.php b/lib/Doctrine/Expression/Oracle.php
index 4cd1c6ff5..34518275a 100644
--- a/lib/Doctrine/Expression/Oracle.php
+++ b/lib/Doctrine/Expression/Oracle.php
@@ -32,22 +32,6 @@ Doctrine::autoload('Doctrine_Expression_Driver');
  */
 class Doctrine_Expression_Oracle extends Doctrine_Expression_Driver
 {
-    /**
-     * Returns a series of strings concatinated
-     *
-     * concat() accepts an arbitrary number of parameters. Each parameter
-     * must contain an expression
-     *
-     * @param string $arg1, $arg2 ... $argN     strings that will be concatinated.
-     * @return string
-     */
-    public function concat()
-    {
-        $args = func_get_args();
-
-        return join(' || ' , $args);
-    }
-
     /**
      * return string to call a function to get a substring inside an SQL statement
      *
@@ -105,4 +89,4 @@ class Doctrine_Expression_Oracle extends Doctrine_Expression_Driver
     {
         return 'SYS_GUID()';
     }
-}
\ No newline at end of file
+}
diff --git a/lib/Doctrine/Expression/Pgsql.php b/lib/Doctrine/Expression/Pgsql.php
index 2451906b5..93400e8c2 100644
--- a/lib/Doctrine/Expression/Pgsql.php
+++ b/lib/Doctrine/Expression/Pgsql.php
@@ -83,17 +83,6 @@ class Doctrine_Expression_Pgsql extends Doctrine_Expression_Driver
         }
     }
 
-    /**
-     * Returns a series of strings concatinated
-     *
-     * concat() accepts an arbitrary number of parameters. Each parameter
-     * must contain an expression or an array with expressions.
-     *
-     * @param string|array(string) strings that will be concatinated.
-     * @return string
-     */
-
-
     /**
      * PostgreSQLs AGE(<timestamp1> [, <timestamp2>]) function.
      *
@@ -131,19 +120,6 @@ class Doctrine_Expression_Pgsql extends Doctrine_Expression_Driver
         return 'TO_CHAR(' . $time . ', ' . $text . ')';
     }
 
-    /**
-     * PostgreSQLs CONCAT() function
-     *
-     * @param  an array of values
-     * @return string
-     */
-    public function concat()
-    {
-        $args = func_get_args();
-
-        return join(' || ' , $args);
-    }
-
     /**
      * Returns the SQL string to return the current system date and time.
      *
@@ -223,4 +199,4 @@ class Doctrine_Expression_Pgsql extends Doctrine_Expression_Driver
         $match.= $this->patternEscapeString();
         return $match;
     }
-}
\ No newline at end of file
+}