diff --git a/typo3/sysext/extensionmanager/Classes/Utility/ListUtility.php b/typo3/sysext/extensionmanager/Classes/Utility/ListUtility.php
index 59c57898c4be5517a2cd9b9fd34d0f75c13a7a39..235435896d3ad4aa3f2c5c5e5e3e179e4e9a0131 100644
--- a/typo3/sysext/extensionmanager/Classes/Utility/ListUtility.php
+++ b/typo3/sysext/extensionmanager/Classes/Utility/ListUtility.php
@@ -107,7 +107,8 @@ class ListUtility implements \TYPO3\CMS\Core\SingletonInterface
      */
     public function getAvailableExtensions()
     {
-        if ($this->availableExtensions === NULL) {
+        if ($this->availableExtensions === null) {
+            $this->availableExtensions = [];
             $this->emitPackagesMayHaveChangedSignal();
             foreach ($this->packageManager->getAvailablePackages() as $package) {
                 $installationType = $this->getInstallTypeForPackage($package);
@@ -123,6 +124,14 @@ class ListUtility implements \TYPO3\CMS\Core\SingletonInterface
         return $this->availableExtensions;
     }
 
+    /**
+     * Reset and reload the available extensions
+     */
+    public function reloadAvailableExtensions() {
+        $this->availableExtensions = null;
+        $this->getAvailableExtensions();
+    }
+
     /**
      * @param string $extensionKey
      * @return \TYPO3\CMS\Core\Package\PackageInterface