diff --git a/src/Phpforce/SoapClient/Result/LoginResult.php b/src/Phpforce/SoapClient/Result/LoginResult.php
index 535868f..87080bb 100644
--- a/src/Phpforce/SoapClient/Result/LoginResult.php
+++ b/src/Phpforce/SoapClient/Result/LoginResult.php
@@ -83,7 +83,7 @@ public function getServerInstance()
         }
 
         $match = preg_match(
-            '/https:\/\/(?<instance>[^-\.]+)/',
+            '/https:\/\/(?<instance>.+).salesforce.com/',
             $this->serverUrl,
             $matches
         );
@@ -94,4 +94,4 @@ public function getServerInstance()
 
         return $matches['instance'];
     }
-}
\ No newline at end of file
+}