diff --git a/basis/unix/unix.factor b/basis/unix/unix.factor
index 76613934af..a6a0147504 100644
--- a/basis/unix/unix.factor
+++ b/basis/unix/unix.factor
@@ -17,6 +17,10 @@ CONSTANT: MAP_FILE    0
 CONSTANT: MAP_SHARED  1
 CONSTANT: MAP_PRIVATE 2
 
+CONSTANT: SEEK_SET 0
+CONSTANT: SEEK_CUR 1
+CONSTANT: SEEK_END 2
+
 : MAP_FAILED ( -- alien ) -1 <alien> ; inline
 
 CONSTANT: NGROUPS_MAX 16