diff --git a/lib/private/Config.php b/lib/private/Config.php
index d69a9837e7543..e48558068b4ef 100644
--- a/lib/private/Config.php
+++ b/lib/private/Config.php
@@ -217,7 +217,8 @@ private function readData() {
 				@opcache_invalidate($file, false);
 			}
 
-			$filePointer = @fopen($file, 'r');
+			// suppressor doesn't work here at boot time since it'll go via our onError custom error handler
+			$filePointer = file_exists($file) ? @fopen($file, 'r') : false;
 			if ($filePointer === false) {
 				// e.g. wrong permissions are set
 				if ($file === $this->configFilePath) {