diff --git a/apps/impress/documentation.php b/apps/impress/documentation.php
index 1047262a677a5882878c20047a93597bb9300a1d..5a153deb4c2df8dd042fe46214452f4fe9489d13 100755
--- a/apps/impress/documentation.php
+++ b/apps/impress/documentation.php
@@ -24,7 +24,7 @@
 require_once('lib/impress.php');
 
 OCP\User::checkLoggedIn();
-OCP\JSON::checkAppEnabled('impress');
+OC_Util::checkAppEnabled('impress');
 OCP\App::setActiveNavigationEntry( 'impress_index' );
 
 
diff --git a/apps/impress/index.php b/apps/impress/index.php
index 8648cb27e7b59b8a9412cda70664ca1cfb37cb6a..59960ba96fa5ccee29e1b0f218384cfbd3759455 100755
--- a/apps/impress/index.php
+++ b/apps/impress/index.php
@@ -24,7 +24,7 @@
 require_once('lib/impress.php');
 
 OCP\User::checkLoggedIn();
-OCP\JSON::checkAppEnabled('impress');
+OC_Util::checkAppEnabled('impress');
 OCP\App::setActiveNavigationEntry( 'impress_index' );
 
 
diff --git a/apps/impress/player.php b/apps/impress/player.php
index 1f2423d856fd5c76669f86b2455059a40047ce86..074badf5df465ab75e8a0f86084d4669485ed1ea 100755
--- a/apps/impress/player.php
+++ b/apps/impress/player.php
@@ -25,7 +25,7 @@ require_once('lib/impress.php');
 
 // Check if we are a user
 OCP\User::checkLoggedIn();
-OCP\JSON::checkAppEnabled('impress');
+OC_Util::checkAppEnabled('impress');
 
 $filename = OCP\Util::sanitizeHTML($_GET['file']);
 $title = OCP\Util::sanitizeHTML($_GET['name']);