diff --git a/ocaml/fstar-lib/FStarC_Parser_LexFStar.ml b/ocaml/fstar-lib/FStarC_Parser_LexFStar.ml
index e4ef505d01f..5943d01b513 100644
--- a/ocaml/fstar-lib/FStarC_Parser_LexFStar.ml
+++ b/ocaml/fstar-lib/FStarC_Parser_LexFStar.ml
@@ -473,6 +473,7 @@ match%sedlex lexbuf with
  | "#print-effects-graph" -> PRAGMA_PRINT_EFFECTS_GRAPH
  | "__SOURCE_FILE__" -> STRING (L.source_file lexbuf)
  | "__LINE__" -> INT (string_of_int (L.current_line lexbuf), false)
+ | "__FL__"   -> STRING ((L.source_file lexbuf) ^ "(" ^ (string_of_int (L.current_line lexbuf)) ^ ")")
 
  | Plus anywhite -> token lexbuf
  | newline -> L.new_line lexbuf; token lexbuf
diff --git a/tests/micro-benchmarks/Test.LexemeFL.fst b/tests/micro-benchmarks/Test.LexemeFL.fst
new file mode 100644
index 00000000000..b289abf8a93
--- /dev/null
+++ b/tests/micro-benchmarks/Test.LexemeFL.fst
@@ -0,0 +1,13 @@
+///  A new lexeme __FL__ has been added to show file and line (file(line)) to make writing tests easier.
+/// This file is line sensitive any edit will change the value of __FL__.
+module Test.LexemeFL
+
+open FStar.String
+module LT = FStar.List.Tot
+// Kinda funky to get a good validation time test, added Strings in other PR will fix this.
+// The lexer is sending back some strange character that we have to adjust.
+let fl = __FL__ 
+let _ = assert(fl <> "")
+let fl'  = string_of_list (list_of_string "Test.LexemFL.fst(11)")
+let _ = assert_norm((strlen fl') = 20)
+let _ = assert_norm(fl' = "Test.LexemFL.fst(11)")