diff --git a/modules/null.mlw b/modules/null.mlw
index c852cf1537bbeec69741a30935df862384297f38..1360d18133bb5ddc2142d39452d755b90587b6fc 100644
--- a/modules/null.mlw
+++ b/modules/null.mlw
@@ -3,7 +3,7 @@
 
     The OCaml driver does optimize this into the identity.
 
-    To permit the implementation of eq_null, null is implemented is a
+    To permit the implementation of eq_null, null is implemented as a
     heap-allocated value in OCaml, e.g., Obj.magic [|0|]
 *)