diff --git a/src/codeBackend.ml b/src/codeBackend.ml
index 14091a8c09e2ad2ad3be07a12f36f9680dcd6538..5ecabd5381903d44d52f6e6f89e2af40663ff8d2 100644
--- a/src/codeBackend.ml
+++ b/src/codeBackend.ml
@@ -295,22 +295,6 @@ let assertnoerror : pattern * expr =
   PUnit,
   EApp (EVar "assert", [ EApp (EVar "not", [ ERecordAccess (EVar env, ferror) ]) ])
 
-let etuple = function
-  | [] ->
-      assert false
-  | [ e ] ->
-      e
-  | es ->
-      ETuple es
-
-let ptuple = function
-  | [] ->
-      assert false
-  | [ p ] ->
-      p
-  | ps ->
-      PTuple ps
-
 let trace (format : string) (args : expr list) : (pattern * expr) list =
   if Settings.trace then
     [ PUnit, EApp (EVar "Printf.fprintf", (EVar "stderr") :: (EStringConst (format ^"\n%!")) :: args) ]
diff --git a/src/codeBits.ml b/src/codeBits.ml
index e4c0617b2c0f491b5b98f5740c21b55aead0293e..ed6e74daf3ab29566b49d5e573f380a041b793a4 100644
--- a/src/codeBits.ml
+++ b/src/codeBits.ml
@@ -16,6 +16,24 @@
 
 open IL
 
+(* Tuples. *)
+
+let etuple = function
+  | [] ->
+      EUnit
+  | [ e ] ->
+      e
+  | es ->
+      ETuple es
+
+let ptuple = function
+  | [] ->
+      PUnit
+  | [ p ] ->
+      p
+  | ps ->
+      PTuple ps
+
 (* A list subject to a condition. *)
 
 let listif condition xs =
diff --git a/src/codeBits.mli b/src/codeBits.mli
index d237dcff2a6ec9a731458255202b4d7068263f44..479124fae52fb17a41dd34ef11f7276d5b1d8835 100644
--- a/src/codeBits.mli
+++ b/src/codeBits.mli
@@ -16,6 +16,11 @@
 
 open IL
 
+(* Tuples. *)
+
+val etuple: expr list -> expr
+val ptuple: pattern list -> pattern
+
 (* A list subject to a condition. (Be careful, though: the list is
    of course constructed even if the condition is false.) *)