diff --git a/plugins/system/httpheaders/httpheaders.php b/plugins/system/httpheaders/httpheaders.php
index b552dd176b912..676668820e06e 100644
--- a/plugins/system/httpheaders/httpheaders.php
+++ b/plugins/system/httpheaders/httpheaders.php
@@ -429,13 +429,13 @@ private function compileAutomaticCspHeaderRules(): array
 			}
 
 			// Append the script hashes placeholder
-			if ($scriptHashesEnabled && strpos($cspValue->directive, 'script-src') === 0)
+			if ($scriptHashesEnabled && strpos($cspHeaderkey, 'script-src') === 0)
 			{
 				$cspHeaderValue = '{script-hashes} ' . $cspHeaderValue;
 			}
 
 			// Append the style hashes placeholder
-			if ($styleHashesEnabled && strpos($cspValue->directive, 'style-src') === 0)
+			if ($styleHashesEnabled && strpos($cspHeaderkey, 'style-src') === 0)
 			{
 				$cspHeaderValue = '{style-hashes} ' . $cspHeaderValue;
 			}