diff --git a/src/MaxCDN/OAuth/OAuthServer.php b/src/MaxCDN/OAuth/OAuthServer.php
index 9379c33..7d284d4 100644
--- a/src/MaxCDN/OAuth/OAuthServer.php
+++ b/src/MaxCDN/OAuth/OAuthServer.php
@@ -84,7 +84,7 @@ private function get_version(&$request) {
             $version = '1.0';
         }
         if ($version !== $this->version) {
-            throw new OAuthException("OAuth version '$version' not supported");
+            throw new \OAuthException("OAuth version '$version' not supported");
         }
         return $version;
     }
@@ -100,12 +100,12 @@ private function get_signature_method($request) {
         if (!$signature_method) {
             // According to chapter 7 ("Accessing Protected Ressources") the signature-method
             // parameter is required, and we can't just fallback to PLAINTEXT
-            throw new OAuthException('No signature method parameter. This parameter is required');
+            throw new \OAuthException('No signature method parameter. This parameter is required');
         }
 
         if (!in_array($signature_method,
                       array_keys($this->signature_methods))) {
-            throw new OAuthException(
+            throw new \OAuthException(
                                      "Signature method '$signature_method' not supported " .
                                      "try one of the following: " .
                                      implode(", ", array_keys($this->signature_methods))
@@ -123,12 +123,12 @@ private function get_consumer($request) {
             : NULL;
 
         if (!$consumer_key) {
-            throw new OAuthException("Invalid consumer key");
+            throw new \OAuthException("Invalid consumer key");
         }
 
         $consumer = $this->data_store->lookup_consumer($consumer_key);
         if (!$consumer) {
-            throw new OAuthException("Invalid consumer");
+            throw new \OAuthException("Invalid consumer");
         }
 
         return $consumer;
@@ -146,7 +146,7 @@ private function get_token($request, $consumer, $token_type="access") {
                                                  $consumer, $token_type, $token_field
                                                 );
         if (!$token) {
-            throw new OAuthException("Invalid $token_type token: $token_field");
+            throw new \OAuthException("Invalid $token_type token: $token_field");
         }
         return $token;
     }
@@ -178,7 +178,7 @@ private function check_signature($request, $consumer, $token) {
                                                        );
 
         if (!$valid_sig) {
-            throw new OAuthException("Invalid signature");
+            throw new \OAuthException("Invalid signature");
         }
     }
 
@@ -187,14 +187,14 @@ private function check_signature($request, $consumer, $token) {
      */
     private function check_timestamp($timestamp) {
         if( ! $timestamp )
-            throw new OAuthException(
+            throw new \OAuthException(
                                      'Missing timestamp parameter. The parameter is required'
                                     );
 
         // verify that timestamp is recentish
         $now = time();
         if (abs($now - $timestamp) > $this->timestamp_threshold) {
-            throw new OAuthException(
+            throw new \OAuthException(
                                      "Expired timestamp, yours $timestamp, ours $now"
                                     );
         }
@@ -205,7 +205,7 @@ private function check_timestamp($timestamp) {
      */
     private function check_nonce($consumer, $token, $nonce, $timestamp) {
         if( ! $nonce )
-            throw new OAuthException(
+            throw new \OAuthException(
                                      'Missing nonce parameter. The parameter is required'
                                     );
 
@@ -217,7 +217,7 @@ private function check_nonce($consumer, $token, $nonce, $timestamp) {
                                                  $timestamp
                                                 );
         if ($found) {
-            throw new OAuthException("Nonce already used: $nonce");
+            throw new \OAuthException("Nonce already used: $nonce");
         }
     }