diff --git a/src/Exception/InvalidGrantException.php b/src/Exception/InvalidGrantException.php
index 89bbaf06..4027a213 100644
--- a/src/Exception/InvalidGrantException.php
+++ b/src/Exception/InvalidGrantException.php
@@ -32,7 +32,7 @@ class InvalidGrantException extends OAuthException
 
     public function __construct($parameter)
     {
-        $this->parameter = parameter;
+        $this->parameter = $parameter;
         parent::__construct(
             sprintf(
                 'The provided authorization grant is invalid, expired, revoked, does not match the redirection URI used in the authorization request, or was issued to another client. Check the "%s" parameter.',
diff --git a/src/Exception/InvalidRequestException.php b/src/Exception/InvalidRequestException.php
index fc45a396..3a682930 100644
--- a/src/Exception/InvalidRequestException.php
+++ b/src/Exception/InvalidRequestException.php
@@ -32,7 +32,7 @@ class InvalidRequestException extends OAuthException
 
     public function __construct($parameter, $redirectUri = null)
     {
-        $this->parameter = parameter;
+        $this->parameter = $parameter;
         parent::__construct(
             sprintf(
                 'The request is missing a required parameter, includes an invalid parameter value, includes a parameter more than once, or is otherwise malformed. Check the "%s" parameter.',
diff --git a/src/Exception/InvalidScopeException.php b/src/Exception/InvalidScopeException.php
index cb437c3b..e70cd692 100644
--- a/src/Exception/InvalidScopeException.php
+++ b/src/Exception/InvalidScopeException.php
@@ -32,7 +32,7 @@ class InvalidScopeException extends OAuthException
 
     public function __construct($parameter, $redirectUri = null)
     {
-        $this->parameter = parameter;
+        $this->parameter = $parameter;
         parent::__construct(
             sprintf(
                 'The requested scope is invalid, unknown, or malformed. Check the "%s" scope.',
diff --git a/src/Exception/OAuthException.php b/src/Exception/OAuthException.php
index e66f16c5..2560d0eb 100644
--- a/src/Exception/OAuthException.php
+++ b/src/Exception/OAuthException.php
@@ -84,7 +84,7 @@ class OAuthException extends \Exception
      */
     public function getParameter()
     {
-        return $this->redirectUri;
+        return $this->parameter;
     }
 
     /**
diff --git a/src/Exception/ServerErrorException.php b/src/Exception/ServerErrorException.php
index 685cc946..70e9532c 100644
--- a/src/Exception/ServerErrorException.php
+++ b/src/Exception/ServerErrorException.php
@@ -31,7 +31,7 @@ class ServerErrorException extends OAuthException
      */
     public function __construct($parameter = null)
     {
-        $this->parameter = parameter;
+        $this->parameter = $parameter;
         $parameter = is_null($parameter) ? 'The authorization server encountered an unexpected condition which prevented it from fulfilling the request.' : $parameter;
         parent::__construct($parameter);
 
diff --git a/src/Exception/UnsupportedGrantTypeException.php b/src/Exception/UnsupportedGrantTypeException.php
index 5b15de5b..b0a33ce3 100644
--- a/src/Exception/UnsupportedGrantTypeException.php
+++ b/src/Exception/UnsupportedGrantTypeException.php
@@ -32,7 +32,7 @@ class UnsupportedGrantTypeException extends OAuthException
 
     public function __construct($parameter)
     {
-        $this->parameter = parameter;
+        $this->parameter = $parameter;
         parent::__construct(
             sprintf(
                 'The authorization grant type "%s" is not supported by the authorization server.',
diff --git a/src/Exception/UnsupportedResponseTypeException.php b/src/Exception/UnsupportedResponseTypeException.php
index 43677d02..663326d1 100644
--- a/src/Exception/UnsupportedResponseTypeException.php
+++ b/src/Exception/UnsupportedResponseTypeException.php
@@ -31,7 +31,7 @@ class UnsupportedResponseTypeException extends OAuthException
      */
     public function __construct($parameter, $redirectUri = null)
     {
-        $this->parameter = parameter;
+        $this->parameter = $parameter;
         parent::__construct('The authorization server does not support obtaining an access token using this method.');
         $this->redirectUri = $redirectUri;
     }