diff --git a/src/proto_alpha/lib_protocol/slash_percentage.ml b/src/proto_alpha/lib_protocol/slash_percentage.ml
index 68c9f28c94aa4bdc4ec9861f03da68852f31b7d6..83e31903dab769c23f16b23666c9bbb71696ea87 100644
--- a/src/proto_alpha/lib_protocol/slash_percentage.ml
+++ b/src/proto_alpha/lib_protocol/slash_percentage.ml
@@ -44,3 +44,7 @@ let get ctxt ~(kind : Misbehaviour_repr.kind) ~(level : Level_repr.t)
   | Double_attesting | Double_preattesting ->
       let* ctxt, rights = Delegate_sampler.attesting_rights_count ctxt level in
       return (ctxt, for_double_attestation ctxt rights denounced)
+
+module Internal_for_tests = struct
+  let for_double_attestation = for_double_attestation
+end
diff --git a/src/proto_alpha/lib_protocol/slash_percentage.mli b/src/proto_alpha/lib_protocol/slash_percentage.mli
index 2f8a71eca8519c6fa8e700ce7cd46561f7559943..3a557576f44ccd3ce39ab855c858c78e9479cc4b 100644
--- a/src/proto_alpha/lib_protocol/slash_percentage.mli
+++ b/src/proto_alpha/lib_protocol/slash_percentage.mli
@@ -20,3 +20,11 @@ val get :
   level:Level_repr.t ->
   Signature.public_key_hash list ->
   (Raw_context.t * Percentage.t) tzresult Lwt.t
+
+module Internal_for_tests : sig
+  val for_double_attestation :
+    Raw_context.t ->
+    int Signature.Public_key_hash.Map.t ->
+    Signature.Public_key_hash.t list ->
+    Percentage.t
+end