diff --git a/src/Peachpie.Library/FileSystem.cs b/src/Peachpie.Library/FileSystem.cs
index c16fb3e6a0..6cff9eaa6a 100644
--- a/src/Peachpie.Library/FileSystem.cs
+++ b/src/Peachpie.Library/FileSystem.cs
@@ -366,9 +366,9 @@ public static PhpValue fgetcsv(PhpResource handle, int length = 0, char delimite
         /// ...
         /// </summary>
         /// <returns>Next line of CSV data or NULL in case of EOF.</returns>
-        delegate string CsvLineReader();
+        internal delegate string CsvLineReader();
 
-        static PhpArray ReadLineCsv(CsvLineReader reader, char delimiter/*=','*/, char enclosure/*='"'*/, char escape_char /*= '\\'*/ )
+        internal static PhpArray ReadLineCsv(CsvLineReader reader, char delimiter/*=','*/, char enclosure/*='"'*/, char escape_char /*= '\\'*/ )
         {
             // collect results
             PhpArray result = new PhpArray();