diff --git a/src/Grant/AbstractGrant.php b/src/Grant/AbstractGrant.php
index 490ecf4c..c6ffc760 100644
--- a/src/Grant/AbstractGrant.php
+++ b/src/Grant/AbstractGrant.php
@@ -80,6 +80,11 @@ abstract class AbstractGrant implements GrantTypeInterface
      */
     protected $pathToPublicKey;
 
+    /**
+     * @var \DateInterval
+     */
+    protected $refreshTokenTTL;
+
     /**
      * @param ClientRepositoryInterface $clientRepository
      */
@@ -128,6 +133,14 @@ abstract class AbstractGrant implements GrantTypeInterface
         $this->emitter = $emitter;
     }
 
+    /**
+     * @inheritdoc
+     */
+    public function setRefreshTokenTTL(\DateInterval $refreshTokenTTL)
+    {
+        $this->refreshTokenTTL = $refreshTokenTTL;
+    }
+
     /**
      * {@inheritdoc}
      */
@@ -291,7 +304,7 @@ abstract class AbstractGrant implements GrantTypeInterface
     {
         $refreshToken = new RefreshTokenEntity();
         $refreshToken->setIdentifier(SecureKey::generate());
-        $refreshToken->setExpiryDateTime((new \DateTime())->add(new \DateInterval('P1M')));
+        $refreshToken->setExpiryDateTime((new \DateTime())->add($this->refreshTokenTTL));
         $refreshToken->setAccessToken($accessToken);
 
         return $refreshToken;
diff --git a/src/Grant/ClientCredentialsGrant.php b/src/Grant/ClientCredentialsGrant.php
index 03c6c721..918586f9 100644
--- a/src/Grant/ClientCredentialsGrant.php
+++ b/src/Grant/ClientCredentialsGrant.php
@@ -32,14 +32,14 @@ class ClientCredentialsGrant extends AbstractGrant
     public function respondToRequest(
         ServerRequestInterface $request,
         ResponseTypeInterface $responseType,
-        \DateInterval $tokenTTL
+        \DateInterval $accessTokenTTL
     ) {
         // Validate request
         $client = $this->validateClient($request);
         $scopes = $this->validateScopes($request, $client);
 
         // Issue and persist access token
-        $accessToken = $this->issueAccessToken($tokenTTL, $client, $client->getIdentifier(), $scopes);
+        $accessToken = $this->issueAccessToken($accessTokenTTL, $client, $client->getIdentifier(), $scopes);
         $this->accessTokenRepository->persistNewAccessToken($accessToken);
 
         // Inject access token into response type
diff --git a/src/Grant/GrantTypeInterface.php b/src/Grant/GrantTypeInterface.php
index 5bc9bf08..a6a5c63a 100644
--- a/src/Grant/GrantTypeInterface.php
+++ b/src/Grant/GrantTypeInterface.php
@@ -11,7 +11,6 @@
 
 namespace League\OAuth2\Server\Grant;
 
-use DateInterval;
 use League\Event\EmitterInterface;
 use League\OAuth2\Server\Repositories\AccessTokenRepositoryInterface;
 use League\OAuth2\Server\Repositories\ClientRepositoryInterface;
@@ -24,6 +23,13 @@ use Psr\Http\Message\ServerRequestInterface;
  */
 interface GrantTypeInterface
 {
+    /**
+     * Set refresh token TTL
+     *
+     * @param \DateInterval $refreshTokenTTL
+     */
+    public function setRefreshTokenTTL(\DateInterval $refreshTokenTTL);
+
     /**
      * Return the identifier
      *
@@ -43,14 +49,14 @@ interface GrantTypeInterface
      *
      * @param \Psr\Http\Message\ServerRequestInterface                  $request
      * @param \League\OAuth2\Server\ResponseTypes\ResponseTypeInterface $responseType
-     * @param \DateInterval                                             $tokenTTL
+     * @param \DateInterval                                             $accessTokenTTL
      *
      * @return \League\OAuth2\Server\ResponseTypes\ResponseTypeInterface
      */
     public function respondToRequest(
         ServerRequestInterface $request,
         ResponseTypeInterface $responseType,
-        DateInterval $tokenTTL
+        \DateInterval $accessTokenTTL
     );
 
     /**
diff --git a/src/Grant/PasswordGrant.php b/src/Grant/PasswordGrant.php
index 50593ef3..9f4f41e8 100644
--- a/src/Grant/PasswordGrant.php
+++ b/src/Grant/PasswordGrant.php
@@ -51,6 +51,8 @@ class PasswordGrant extends AbstractGrant
     ) {
         $this->userRepository = $userRepository;
         $this->refreshTokenRepository = $refreshTokenRepository;
+
+        $this->refreshTokenTTL = new \DateInterval('P1M');
     }
 
     /**
@@ -59,7 +61,7 @@ class PasswordGrant extends AbstractGrant
     public function respondToRequest(
         ServerRequestInterface $request,
         ResponseTypeInterface $responseType,
-        \DateInterval $tokenTTL
+        \DateInterval $accessTokenTTL
     ) {
         // Validate request
         $client = $this->validateClient($request);
@@ -67,7 +69,7 @@ class PasswordGrant extends AbstractGrant
         $scopes = $this->validateScopes($request, $client);
 
         // Issue and persist new tokens
-        $accessToken = $this->issueAccessToken($tokenTTL, $client, $user->getIdentifier(), $scopes);
+        $accessToken = $this->issueAccessToken($accessTokenTTL, $client, $user->getIdentifier(), $scopes);
         $refreshToken = $this->issueRefreshToken($accessToken);
         $this->accessTokenRepository->persistNewAccessToken($accessToken);
         $this->refreshTokenRepository->persistNewRefreshToken($refreshToken);
diff --git a/src/Grant/RefreshTokenGrant.php b/src/Grant/RefreshTokenGrant.php
index d8348d25..cf3286c8 100644
--- a/src/Grant/RefreshTokenGrant.php
+++ b/src/Grant/RefreshTokenGrant.php
@@ -42,6 +42,8 @@ class RefreshTokenGrant extends AbstractGrant
         RefreshTokenRepositoryInterface $refreshTokenRepository
     ) {
         $this->refreshTokenRepository = $refreshTokenRepository;
+
+        $this->refreshTokenTTL = new \DateInterval('P1M');
     }
 
     /**
@@ -50,8 +52,9 @@ class RefreshTokenGrant extends AbstractGrant
     public function respondToRequest(
         ServerRequestInterface $request,
         ResponseTypeInterface $responseType,
-        \DateInterval $tokenTTL
+        \DateInterval $accessTokenTTL
     ) {
+        // Validate request
         $client          = $this->validateClient($request);
         $oldRefreshToken = $this->validateOldRefreshToken($request, $client->getIdentifier());
         $scopes          = $this->validateScopes($request, $client);
@@ -75,9 +78,9 @@ class RefreshTokenGrant extends AbstractGrant
         $this->accessTokenRepository->revokeAccessToken($oldRefreshToken['access_token_id']);
         $this->refreshTokenRepository->revokeRefreshToken($oldRefreshToken['refresh_token_id']);
 
-        $accessToken = $this->issueAccessToken($tokenTTL, $client, $oldRefreshToken['user_id'], $scopes);
+        // Issue and persist new tokens
+        $accessToken = $this->issueAccessToken($accessTokenTTL, $client, $oldRefreshToken['user_id'], $scopes);
         $refreshToken = $this->issueRefreshToken($accessToken);
-
         $this->accessTokenRepository->persistNewAccessToken($accessToken);
         $this->refreshTokenRepository->persistNewRefreshToken($refreshToken);
 
diff --git a/src/Server.php b/src/Server.php
index a62e8b32..adb6936d 100644
--- a/src/Server.php
+++ b/src/Server.php
@@ -7,6 +7,7 @@ use League\Event\EmitterAwareInterface;
 use League\Event\EmitterAwareTrait;
 use League\OAuth2\Server\Exception\OAuthServerException;
 use League\OAuth2\Server\Grant\GrantTypeInterface;
+use League\OAuth2\Server\Grant\ClientCredentialsGrant;
 use League\OAuth2\Server\Repositories\AccessTokenRepositoryInterface;
 use League\OAuth2\Server\Repositories\ClientRepositoryInterface;
 use League\OAuth2\Server\Repositories\ScopeRepositoryInterface;
@@ -26,11 +27,6 @@ class Server implements EmitterAwareInterface
      */
     protected $enabledGrantTypes = [];
 
-    /**
-     * @var ResponseTypeInterface[]
-     */
-    protected $grantResponseTypes = [];
-
     /**
      * @var DateInterval[]
      */
@@ -92,47 +88,23 @@ class Server implements EmitterAwareInterface
         $this->responseType = $responseType;
     }
 
-    /**
-     * Get the token type that grants will return in the HTTP response
-     *
-     * @return ResponseTypeInterface
-     */
-    public function getResponseType()
-    {
-        if (!$this->responseType instanceof ResponseTypeInterface) {
-            $this->responseType = new BearerTokenResponse(
-                $this->privateKeyPath,
-                $this->publicKeyPath,
-                $this->accessTokenRepository
-            );
-        }
-
-        return $this->responseType;
-    }
-
     /**
      * Enable a grant type on the server
      *
      * @param \League\OAuth2\Server\Grant\GrantTypeInterface $grantType
      * @param DateInterval                                   $accessTokenTTL
      */
-    public function enableGrantType(
-        GrantTypeInterface $grantType,
-        \DateInterval $accessTokenTTL
-    ) {
+    public function enableGrantType(GrantTypeInterface $grantType, \DateInterval $accessTokenTTL)
+    {
         $grantType->setAccessTokenRepository($this->accessTokenRepository);
         $grantType->setClientRepository($this->clientRepository);
         $grantType->setScopeRepository($this->scopeRepository);
         $grantType->setPathToPrivateKey($this->privateKeyPath);
         $grantType->setPathToPublicKey($this->publicKeyPath);
-
         $grantType->setEmitter($this->getEmitter());
+
         $this->enabledGrantTypes[$grantType->getIdentifier()] = $grantType;
 
-        // Set grant response type
-        $this->grantResponseTypes[$grantType->getIdentifier()] = $this->getResponseType();
-
-        // Set grant access token TTL
         $this->grantTypeAccessTokenTTL[$grantType->getIdentifier()] = $accessTokenTTL;
     }
 
@@ -160,7 +132,7 @@ class Server implements EmitterAwareInterface
             if ($grantType->canRespondToRequest($request)) {
                 $tokenResponse = $grantType->respondToRequest(
                     $request,
-                    $this->grantResponseTypes[$grantType->getIdentifier()],
+                    $this->getResponseType(),
                     $this->grantTypeAccessTokenTTL[$grantType->getIdentifier()]
                 );
             }
@@ -172,4 +144,22 @@ class Server implements EmitterAwareInterface
 
         return $tokenResponse->generateHttpResponse($response);
     }
+
+    /**
+     * Get the token type that grants will return in the HTTP response
+     *
+     * @return ResponseTypeInterface
+     */
+    public function getResponseType()
+    {
+        if (!$this->responseType instanceof ResponseTypeInterface) {
+            $this->responseType = new BearerTokenResponse(
+                $this->privateKeyPath,
+                $this->publicKeyPath,
+                $this->accessTokenRepository
+            );
+        }
+
+        return $this->responseType;
+    }
 }