diff --git a/lib/archethic/contracts/interpreter/library/common/contract.ex b/lib/archethic/contracts/interpreter/library/common/contract.ex
index c11e38554..522ff3779 100644
--- a/lib/archethic/contracts/interpreter/library/common/contract.ex
+++ b/lib/archethic/contracts/interpreter/library/common/contract.ex
@@ -6,7 +6,6 @@ defmodule Archethic.Contracts.Interpreter.Library.Common.Contract do
   """
   @behaviour Archethic.Contracts.Interpreter.Library
 
-  alias Archethic.Contracts
   alias Archethic.Contracts.Interpreter.ASTHelper, as: AST
   alias Archethic.Contracts.Interpreter.Legacy.UtilsInterpreter
   alias Archethic.Contracts.Interpreter.Legacy.TransactionStatements
@@ -21,6 +20,13 @@ defmodule Archethic.Contracts.Interpreter.Library.Common.Contract do
 
   use Tag
 
+  # we do not use knigge because we do not mock the entire module
+  @contract_impl Application.compile_env(
+                   :archethic,
+                   __MODULE__,
+                   Archethic.Contracts.Interpreter.Library.Common.ContractImpl
+                 )
+
   @tag [:write_contract]
   @spec set_type(Transaction.t(), binary()) :: Transaction.t()
   defdelegate set_type(next_tx, type),
@@ -128,28 +134,8 @@ defmodule Archethic.Contracts.Interpreter.Library.Common.Contract do
   @tag [:io]
   @spec call_function(address :: binary(), function :: binary(), args :: list()) :: any()
   def call_function(address, function, args) do
-    address = UtilsInterpreter.get_address(address, :call_function)
-
-    unless is_binary(function),
-      do:
-        raise(Library.Error,
-          message: "Contract.call_function must have binary function got #{inspect(function)}"
-        )
-
-    unless is_list(args),
-      do:
-        raise(Library.Error,
-          message: "Contract.call_function must have list for args got #{inspect(args)}"
-        )
-
-    with {:ok, tx} <- Archethic.get_last_transaction(address),
-         {:ok, contract} <- Contracts.from_transaction(tx),
-         {:ok, result} <- Contracts.execute_function(contract, function, args) do
-      result
-    else
-      {:error, reason} ->
-        raise(Library.Error, message: "Contract.call_function failed with #{inspect(reason)}")
-    end
+    # for some reason I failed to use defdelegate
+    apply(@contract_impl, :call_function, [address, function, args])
   end
 
   # We do not need to check the transaction argument because _we_ are feeding it (after this step)
diff --git a/lib/archethic/contracts/interpreter/library/common/contract_impl.ex b/lib/archethic/contracts/interpreter/library/common/contract_impl.ex
new file mode 100644
index 000000000..6801cc628
--- /dev/null
+++ b/lib/archethic/contracts/interpreter/library/common/contract_impl.ex
@@ -0,0 +1,38 @@
+defmodule Archethic.Contracts.Interpreter.Library.Common.ContractImpl do
+  @moduledoc """
+  this is not a behaviour because we define only few functions
+  """
+
+  alias Archethic.Contracts
+  alias Archethic.Contracts.Interpreter.Legacy.UtilsInterpreter
+  alias Archethic.Contracts.Interpreter.Library
+
+  use Archethic.Tag
+
+  @tag [:io]
+  @spec call_function(address :: binary(), function :: binary(), args :: list()) :: any()
+  def call_function(address, function, args) do
+    address = UtilsInterpreter.get_address(address, :call_function)
+
+    unless is_binary(function),
+      do:
+        raise(Library.Error,
+          message: "Contract.call_function must have binary function got #{inspect(function)}"
+        )
+
+    unless is_list(args),
+      do:
+        raise(Library.Error,
+          message: "Contract.call_function must have list for args got #{inspect(args)}"
+        )
+
+    with {:ok, tx} <- Archethic.get_last_transaction(address),
+         {:ok, contract} <- Contracts.from_transaction(tx),
+         {:ok, result} <- Contracts.execute_function(contract, function, args) do
+      result
+    else
+      {:error, reason} ->
+        raise(Library.Error, message: "Contract.call_function failed with #{inspect(reason)}")
+    end
+  end
+end