diff --git a/bigarray/sequenceBigarray.ml b/bigarray/sequenceBigarray.ml
index fd61b86..6f9c19f 100644
--- a/bigarray/sequenceBigarray.ml
+++ b/bigarray/sequenceBigarray.ml
@@ -36,7 +36,7 @@ let mmap filename =
     let fd = Unix.openfile filename [Unix.O_RDONLY] 0 in
     let len = Unix.lseek fd 0 Unix.SEEK_END in
     let _ = Unix.lseek fd 0 Unix.SEEK_SET in
-    let b = Bigarray.Array1.map_file fd Bigarray.Char Bigarray.C_layout false len in
+    let b = Bigarray.Array1.map_file fd Bigarray.char Bigarray.c_layout false len in
     try
       of_bigarray b yield;
       Unix.close fd