diff --git a/rtl/objpas/classes/classesh.inc b/rtl/objpas/classes/classesh.inc
index abea95ef2c..5e64b44b3c 100644
--- a/rtl/objpas/classes/classesh.inc
+++ b/rtl/objpas/classes/classesh.inc
@@ -1187,6 +1187,7 @@ type
     constructor Create(const AFileName: string; Mode: Word);
     constructor Create(const AFileName: string; Mode: Word; Rights: Cardinal);
     destructor Destroy; override;
+    Function Flush : Boolean;
     property FileName : String Read FFilename;
   end;
 
diff --git a/rtl/objpas/classes/streams.inc b/rtl/objpas/classes/streams.inc
index 4fda17b2e5..0ec3500518 100644
--- a/rtl/objpas/classes/streams.inc
+++ b/rtl/objpas/classes/streams.inc
@@ -1336,6 +1336,11 @@ begin
   FileClose(FHandle);
 end;
 
+function TFileStream.Flush : Boolean;
+begin
+  Result:=FileFlush(Handle);
+end;
+
 {****************************************************************************}
 {*                             TCustomMemoryStream                          *}
 {****************************************************************************}