diff --git a/index.php b/index.php
index eeecb25c..69c1d161 100644
--- a/index.php
+++ b/index.php
@@ -1284,7 +1284,6 @@ public function isAuthenticated(): bool {
 	if (isset($_POST['step'])) {
 		// mark step as failed
 		http_response_code(500);
-		header('Content-Type: application/json');
 		echo(json_encode(['proceed' => false, 'response' => $e->getMessage()]));
 		die();
 	}
@@ -1371,7 +1370,6 @@ public function isAuthenticated(): bool {
 				break;
 		}
 		$updater->endStep($step);
-		header('Content-Type: application/json');
 		echo(json_encode(['proceed' => true]));
 	} catch (UpdateException $e) {
 		$data = $e->getData();
@@ -1387,7 +1385,6 @@ public function isAuthenticated(): bool {
 			$updater->rollbackChanges($step);
 		}
 		http_response_code(500);
-		header('Content-Type: application/json');
 		echo(json_encode(['proceed' => false, 'response' => $data]));
 	} catch (\Exception $e) {
 		$message = $e->getMessage();
@@ -1403,7 +1400,6 @@ public function isAuthenticated(): bool {
 			$updater->rollbackChanges($step);
 		}
 		http_response_code(500);
-		header('Content-Type: application/json');
 		echo(json_encode(['proceed' => false, 'response' => $message]));
 	}
 
diff --git a/tests/features/master.feature b/tests/features/master.feature
index 0bc2bea1..4028dc9d 100644
--- a/tests/features/master.feature
+++ b/tests/features/master.feature
@@ -7,6 +7,6 @@ Feature: CLI updater - master base
     And the version number is decreased in the config.php to enforce upgrade
     When the CLI updater is run successfully
     And the output should contain "Update successful"
-    Then the installed version should be 28.0
+    Then the installed version should be 29.0
     And maintenance mode should be off
     And upgrade is not required
diff --git a/updater.phar b/updater.phar
index ddba9d5c..d3eb6c6c 100755
Binary files a/updater.phar and b/updater.phar differ