diff --git a/frontends/LexOccam.x b/frontends/LexOccam.x
index 4986663..4354ffb 100644
--- a/frontends/LexOccam.x
+++ b/frontends/LexOccam.x
@@ -1,4 +1,4 @@
-{ {-# OPTIONS_GHC -fno-warn-unused-imports #-}
+{ {-# OPTIONS_GHC -fno-warn-unused-imports -fno-warn-tabs #-}
 {-
 Tock: a compiler for parallel languages
 Copyright (C) 2007  University of Kent
diff --git a/frontends/LexRain.x b/frontends/LexRain.x
index 9d3b652..44c341c 100644
--- a/frontends/LexRain.x
+++ b/frontends/LexRain.x
@@ -1,4 +1,4 @@
-{ {-# OPTIONS_GHC -fno-warn-unused-imports #-}
+{ {-# OPTIONS_GHC -fno-warn-unused-imports -fno-warn-tabs #-}
 {-
 Tock: a compiler for parallel languages
 Copyright (C) 2007  University of Kent