diff --git a/sledge/nonstdlib/NS.ml b/sledge/nonstdlib/NS.ml
index 39acfe3ee..5c8f0be9c 100644
--- a/sledge/nonstdlib/NS.ml
+++ b/sledge/nonstdlib/NS.ml
@@ -137,7 +137,7 @@ module IArray = IArray
 include IArray.Import
 module Set = Set
 module Map = Map
-module Qset = Qset
+module Multiset = Multiset
 
 (** Data types *)
 
diff --git a/sledge/nonstdlib/NS.mli b/sledge/nonstdlib/NS.mli
index 67089c549..93c60e13a 100644
--- a/sledge/nonstdlib/NS.mli
+++ b/sledge/nonstdlib/NS.mli
@@ -109,7 +109,7 @@ module IArray = IArray
 include module type of IArray.Import
 module Set = Set
 module Map = Map
-module Qset = Qset
+module Multiset = Multiset
 
 (** Data types *)
 
diff --git a/sledge/nonstdlib/qset.ml b/sledge/nonstdlib/multiset.ml
similarity index 96%
rename from sledge/nonstdlib/qset.ml
rename to sledge/nonstdlib/multiset.ml
index 50f584178..b839c2c36 100644
--- a/sledge/nonstdlib/qset.ml
+++ b/sledge/nonstdlib/multiset.ml
@@ -5,10 +5,10 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-(** Qset - Set with (signed) rational multiplicity for each element *)
+(** Multiset - Set with (signed) rational multiplicity for each element *)
 
 open NS0
-include Qset_intf
+include Multiset_intf
 
 module Make (Elt : sig
   type t [@@deriving compare, sexp_of]
diff --git a/sledge/nonstdlib/qset.mli b/sledge/nonstdlib/multiset.mli
similarity index 71%
rename from sledge/nonstdlib/qset.mli
rename to sledge/nonstdlib/multiset.mli
index 1ee52139d..838389a78 100644
--- a/sledge/nonstdlib/qset.mli
+++ b/sledge/nonstdlib/multiset.mli
@@ -5,9 +5,9 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-(** Qset - Set with (signed) rational multiplicity for each element *)
+(** Multiset - Set with (signed) rational multiplicity for each element *)
 
-include module type of Qset_intf
+include module type of Multiset_intf
 
 module Make (Elt : sig
   type t [@@deriving compare, sexp_of]
diff --git a/sledge/nonstdlib/qset_intf.ml b/sledge/nonstdlib/multiset_intf.ml
similarity index 97%
rename from sledge/nonstdlib/qset_intf.ml
rename to sledge/nonstdlib/multiset_intf.ml
index 8db51e830..d2428efbc 100644
--- a/sledge/nonstdlib/qset_intf.ml
+++ b/sledge/nonstdlib/multiset_intf.ml
@@ -5,7 +5,7 @@
  * LICENSE file in the root directory of this source tree.
  *)
 
-(** Qset - Set with (signed) rational multiplicity for each element *)
+(** Multiset - Set with (signed) rational multiplicity for each element *)
 
 open NS0
 
diff --git a/sledge/src/ses/term.ml b/sledge/src/ses/term.ml
index db8a666d5..8fffa151d 100644
--- a/sledge/src/ses/term.ml
+++ b/sledge/src/ses/term.ml
@@ -44,11 +44,11 @@ end = struct
 end
 
 and Qset : sig
-  include NS.Qset.S with type elt := T.t
+  include NS.Multiset.S with type elt := T.t
 
   val t_of_sexp : Sexp.t -> t
 end = struct
-  include NS.Qset.Make (T)
+  include NS.Multiset.Make (T)
 
   let t_of_sexp = t_of_sexp T.t_of_sexp
 end
diff --git a/sledge/src/ses/term.mli b/sledge/src/ses/term.mli
index ae39a60c4..39d128b6c 100644
--- a/sledge/src/ses/term.mli
+++ b/sledge/src/ses/term.mli
@@ -57,7 +57,7 @@ module rec Set : sig
 end
 
 and Qset : sig
-  include NS.Qset.S with type elt := T.t
+  include NS.Multiset.S with type elt := T.t
 
   val t_of_sexp : Sexp.t -> t
 end