diff --git a/src/Generalization.ml b/src/Generalization.ml
index f05e6094069196069e8974ffe958aff70ef24fb0..47418b5aef2e4409db6e9cdc244b21534ef69b9b 100644
--- a/src/Generalization.ml
+++ b/src/Generalization.ml
@@ -11,7 +11,7 @@
 
 open Signatures
 
-module Make (S : STRUCTURE_OPT) = struct
+module Make (S : GSTRUCTURE_OPT) = struct
 
 (* -------------------------------------------------------------------------- *)
 
diff --git a/src/Generalization.mli b/src/Generalization.mli
index 7f7a519f0f5baf5357d06ae8c3e744f16556516e..89d94547b468af4123e14f2dd493662749a0942e 100644
--- a/src/Generalization.mli
+++ b/src/Generalization.mli
@@ -22,7 +22,7 @@ open Signatures
    operations that allow constructing, inspecting, and instantiating
    schemes. *)
 module Make
-  (S : sig (** @inline *) include STRUCTURE_OPT end)
+  (S : sig (** @inline *) include GSTRUCTURE_OPT end)
 : sig
 
   (** {2 Unification} *)
diff --git a/src/Signatures.ml b/src/Signatures.ml
index 2cf44205aca7132f6d1eb55478da396bda52c324..461a73ec3aedf8b1a2e3f57f4cd88ee9402a0c35 100644
--- a/src/Signatures.ml
+++ b/src/Signatures.ml
@@ -190,10 +190,10 @@ module type GSTRUCTURE = sig
 
 end
 
-(* [STRUCTURE_OPT] describes the output of [Structure.Option] and
+(* [GSTRUCTURE_OPT] describes the output of [Structure.Option] and
    an input of [Generalization.Make]. *)
 
-module type STRUCTURE_OPT = sig
+module type GSTRUCTURE_OPT = sig
 
   module S : GSTRUCTURE
 
diff --git a/src/Structure.mli b/src/Structure.mli
index a3e02fbff0d172e7473f57b756b11f15ca1f8857..1c52bd53aeccf5f70d20d5f45845135a9246d1f2 100644
--- a/src/Structure.mli
+++ b/src/Structure.mli
@@ -21,6 +21,6 @@ open Signatures
 module Option (S : sig (** @inline *) include GSTRUCTURE end) : sig
 
   (** @inline *)
-  include STRUCTURE_OPT with module S = S
+  include GSTRUCTURE_OPT with module S = S
 
 end