diff --git a/packages/fcl-json/src/jsonscanner.pp b/packages/fcl-json/src/jsonscanner.pp
index 79a00c1bf5..e6b6169e6c 100644
--- a/packages/fcl-json/src/jsonscanner.pp
+++ b/packages/fcl-json/src/jsonscanner.pp
@@ -631,7 +631,7 @@ end;
 function TJSONScanner.GetAbsolutePos: Integer;
 
 begin
-  Result:=FCurPos-PChar(FSource);
+  Result:=FCurPos-PAnsiChar(FSource);
 end;
 
 procedure TJSONScanner.SetO(AIndex: TJSONOption; AValue: Boolean);