diff --git a/AUDIT.md b/AUDIT.md
index cbd5d79..e7d303e 100644
--- a/AUDIT.md
+++ b/AUDIT.md
@@ -43,6 +43,7 @@ after each item.
 - [x] `scripting/job_store.ex`
 - [x] `desktop/server.ex`
 - [x] `desktop/shell_live/code_entity_editor.ex`
+- [x] `scripting/runtime.ex`
 
 ---
 
diff --git a/lib/bds/scripting.ex b/lib/bds/scripting.ex
index 40cb452..cb42dfb 100644
--- a/lib/bds/scripting.ex
+++ b/lib/bds/scripting.ex
@@ -6,7 +6,7 @@ defmodule BDS.Scripting do
   require Logger
 
   alias BDS.Scripting.Capabilities
-  alias BDS.Scripting.Runtime
+  alias BDS.Scripting.Lua
 
   @type job_status :: :queued | :running | :completed | :failed | :cancelled
   @type job_snapshot :: %{
@@ -31,7 +31,7 @@ defmodule BDS.Scripting do
     runtime().validate(source)
   end
 
-  @spec execute(String.t(), String.t(), [term()], [Runtime.execution_option()]) ::
+  @spec execute(String.t(), String.t(), [term()], [Lua.execution_option()]) ::
           {:ok, term()} | {:error, term()}
   def execute(source, entrypoint, args \\ [], opts \\ [])
       when is_binary(source) and is_binary(entrypoint) and is_list(args) and is_list(opts) do
@@ -39,7 +39,7 @@ defmodule BDS.Scripting do
   end
 
   @spec execute_project_script(String.t(), String.t(), String.t(), [term()], [
-          Runtime.execution_option()
+          Lua.execution_option()
         ]) ::
           {:ok, term()} | {:error, term()}
   def execute_project_script(project_id, source, entrypoint, args \\ [], opts \\ [])
@@ -75,7 +75,7 @@ defmodule BDS.Scripting do
     end
   end
 
-  @spec start_job(String.t(), String.t(), [term()], [Runtime.execution_option()]) ::
+  @spec start_job(String.t(), String.t(), [term()], [Lua.execution_option()]) ::
           {:ok, job_snapshot()} | {:error, term()}
   def start_job(source, entrypoint, args \\ [], opts \\ [])
       when is_binary(source) and is_binary(entrypoint) and is_list(args) and is_list(opts) do
diff --git a/lib/bds/scripting/lua.ex b/lib/bds/scripting/lua.ex
index d77fe60..76c240a 100644
--- a/lib/bds/scripting/lua.ex
+++ b/lib/bds/scripting/lua.ex
@@ -6,7 +6,23 @@ defmodule BDS.Scripting.Lua do
   and opt-in.
   """
 
-  @behaviour BDS.Scripting.Runtime
+  @type source :: String.t()
+  @type entrypoint :: String.t()
+  @type args :: [term()]
+  @type progress_event :: map()
+  @type progress_callback :: (progress_event() -> any())
+  @type execution_option ::
+          {:timeout, non_neg_integer() | :infinity}
+          | {:max_reductions, pos_integer() | :none}
+          | {:spawn_opts, [term()]}
+          | {:on_progress, progress_callback()}
+          | {:capabilities, map()}
+
+  @callback validate(source()) :: :ok | {:error, term()}
+  @callback execute(source(), entrypoint(), args(), [execution_option()]) ::
+              {:ok, term()} | {:error, term()}
+
+  @behaviour __MODULE__
 
   @type lua_state :: tuple()
   @type runtime_result :: {:ok, term(), lua_state} | {:error, term()}
diff --git a/lib/bds/scripting/runtime.ex b/lib/bds/scripting/runtime.ex
deleted file mode 100644
index d1432b3..0000000
--- a/lib/bds/scripting/runtime.ex
+++ /dev/null
@@ -1,24 +0,0 @@
-defmodule BDS.Scripting.Runtime do
-  @moduledoc """
-  Behaviour for user-script runtimes hosted by bDS.
-
-  The runtime boundary is intentionally narrow: syntax validation and
-  bounded entrypoint execution.
-  """
-
-  @type source :: String.t()
-  @type entrypoint :: String.t()
-  @type args :: [term()]
-  @type progress_event :: map()
-  @type progress_callback :: (progress_event() -> any())
-  @type execution_option ::
-          {:timeout, non_neg_integer() | :infinity}
-          | {:max_reductions, pos_integer() | :none}
-          | {:spawn_opts, [term()]}
-          | {:on_progress, progress_callback()}
-          | {:capabilities, map()}
-
-  @callback validate(source()) :: :ok | {:error, term()}
-  @callback execute(source(), entrypoint(), args(), [execution_option()]) ::
-              {:ok, term()} | {:error, term()}
-end
diff --git a/test/bds/scripting/job_test.exs b/test/bds/scripting/job_test.exs
index 41d0f0b..3e21a20 100644
--- a/test/bds/scripting/job_test.exs
+++ b/test/bds/scripting/job_test.exs
@@ -2,7 +2,7 @@ defmodule BDS.Scripting.JobTest do
   use ExUnit.Case, async: false
 
   defmodule FakeRuntime do
-    @behaviour BDS.Scripting.Runtime
+    @behaviour BDS.Scripting.Lua
 
     @impl true
     def validate(_source), do: :ok
@@ -19,7 +19,7 @@ defmodule BDS.Scripting.JobTest do
   end
 
   defmodule BlockingRuntime do
-    @behaviour BDS.Scripting.Runtime
+    @behaviour BDS.Scripting.Lua
 
     @impl true
     def validate(_source), do: :ok
@@ -37,7 +37,7 @@ defmodule BDS.Scripting.JobTest do
   end
 
   defmodule ShutdownAwareRuntime do
-    @behaviour BDS.Scripting.Runtime
+    @behaviour BDS.Scripting.Lua
 
     @impl true
     def validate(_source), do: :ok