diff --git a/src/denomination.ml b/src/denomination.ml
index 710f8921..e1aabbc8 100644
--- a/src/denomination.ml
+++ b/src/denomination.ml
@@ -16,6 +16,23 @@ type t = {
   master_sig: Signatures.DenominationKeyValidity.t;
 }
 
+let verify_denomination_key_validity ~key dn =
+  let open Signatures.DenominationKeyValidity in
+  verify key dn.master_sig
+    {
+      R.master= key;
+      start= dn.stamp_start;
+      expire_withdraw= dn.stamp_expire_withdraw;
+      expire_spend= dn.stamp_expire_deposit;
+      expire_legal= dn.stamp_expire_legal;
+      value= dn.value;
+      fee_withdraw= dn.fee_withdraw;
+      fee_deposit= dn.fee_deposit;
+      fee_refresh= dn.fee_refresh;
+      fee_refund= dn.fee_refund;
+      denom_hash= dn.h_pub;
+    }
+
 let make_denom_group_sorted denominations =
   let open Syntax in
   (* use hashtbl to re-group denoms *)
diff --git a/src/keys.ml b/src/keys.ml
index 499e7709..2c32e2ae 100644
--- a/src/keys.ml
+++ b/src/keys.ml
@@ -288,7 +288,8 @@ module Make (Conn : Pg.CONN) : S = struct
       =
     let* fdn = find_future_denomination h_denom_pub in
     let dn = dn_of_future_dn fdn h_denom_pub master_sig in
-    Verify_signature.denomination_key_validity ~key:Config.master_public_key dn
+    Denomination.verify_denomination_key_validity ~key:Config.master_public_key
+      dn
 
   let certify_future_signkey Api.SignKeySignature.{ key= pub; master_sig } =
     match Sm_eddsa.find_key pub with
diff --git a/src/verify_signature.ml b/src/verify_signature.ml
deleted file mode 100644
index feee28fe..00000000
--- a/src/verify_signature.ml
+++ /dev/null
@@ -1,17 +0,0 @@
-let denomination_key_validity ~key dn =
-  let open Denomination in
-  let open Signatures.DenominationKeyValidity in
-  verify key dn.master_sig
-    {
-      R.master= key;
-      start= dn.stamp_start;
-      expire_withdraw= dn.stamp_expire_withdraw;
-      expire_spend= dn.stamp_expire_deposit;
-      expire_legal= dn.stamp_expire_legal;
-      value= dn.value;
-      fee_withdraw= dn.fee_withdraw;
-      fee_deposit= dn.fee_deposit;
-      fee_refresh= dn.fee_refresh;
-      fee_refund= dn.fee_refund;
-      denom_hash= dn.h_pub;
-    }
diff --git a/test/validate_response.ml b/test/validate_response.ml
index e25cfeb9..068eaa57 100644
--- a/test/validate_response.ml
+++ b/test/validate_response.ml
@@ -77,7 +77,8 @@ let keys content =
   let* () =
     denom_l
     |> list_iter (fun dn ->
-        Verify_signature.denomination_key_validity ~key:v.master_public_key dn)
+        Denomination.verify_denomination_key_validity ~key:v.master_public_key
+          dn)
   in
   let* () =
     let last_issue_date =