diff --git a/lib/Horde/ActiveSync/Imap/Adapter.php b/lib/Horde/ActiveSync/Imap/Adapter.php
index 4f564b24..dfc103dd 100644
--- a/lib/Horde/ActiveSync/Imap/Adapter.php
+++ b/lib/Horde/ActiveSync/Imap/Adapter.php
@@ -1218,15 +1218,23 @@ protected function _doQuery(array $query, array $options, bool $deepTraversal):
      * is not yet authenticated at the time of object creation.
      *
      * @return Horde_Imap_Client_Base
-     * @throws Horde_ActiveSync_Exception
+     * @throws Horde_Exception_AuthenticationFailure
      */
     protected function _getImapOb()
     {
+        $message = 'EMERGENCY - Unable to obtain the IMAP Client';
+
         try {
-            return $this->_imap->getImapOb();
+            $imap = $this->_imap->getImapOb();
         } catch (Horde_ActiveSync_Exception $e) {
-            throw new Horde_Exception_AuthenticationFailure('EMERGENCY - Unable to obtain the IMAP Client');
+            throw new Horde_Exception_AuthenticationFailure($message, 0, $e);
         }
+
+        if (empty($imap)) {
+            throw new Horde_Exception_AuthenticationFailure($message);
+        }
+
+        return $imap;
     }
 
     /**
diff --git a/test/unit/Horde/ActiveSync/ImapAdapterTest.php b/test/unit/Horde/ActiveSync/ImapAdapterTest.php
index c9673eea..f213f731 100644
--- a/test/unit/Horde/ActiveSync/ImapAdapterTest.php
+++ b/test/unit/Horde/ActiveSync/ImapAdapterTest.php
@@ -59,6 +59,18 @@ public function testPingUsesPingWatermarkNotSyncModseq()
         $this->assertEquals(6000, $folder->pingModseq());
     }
 
+    public function testPingThrowsAuthenticationFailureWhenImapClientIsNull()
+    {
+        $adapter = new Horde_ActiveSync_Imap_Adapter([
+            'factory' => $this->_imapFactoryFixture(null),
+        ]);
+        $folder = new Horde_ActiveSync_Folder_Imap('INBOX', Horde_ActiveSync::CLASS_EMAIL);
+
+        $this->expectException(\Horde_Exception_AuthenticationFailure::class);
+
+        $adapter->ping($folder);
+    }
+
     public function testBug13711()
     {
         Bug13711Fixtures::setActiveSyncProtocolVersion('14.1');