diff --git a/src/commands/signal-handler.test.ts b/src/commands/signal-handler.test.ts
index 4b1b9622b..0f4435311 100644
--- a/src/commands/signal-handler.test.ts
+++ b/src/commands/signal-handler.test.ts
@@ -1,4 +1,6 @@
-import { registerSignalHandlers, SignalHandlerDependencies } from './signal-handler';
+import { registerSignalHandlers } from './signal-handler';
+
+type SignalHandlerDependencies = Parameters<typeof registerSignalHandlers>[0];
 
 const flushPromises = (): Promise<void> => new Promise(resolve => setImmediate(resolve));
 
@@ -158,4 +160,3 @@ describe('registerSignalHandlers', () => {
     expect(processExitSpy).toHaveBeenCalledWith(143);
   });
 });
-
diff --git a/src/commands/signal-handler.ts b/src/commands/signal-handler.ts
index 278988695..8e69e7eea 100644
--- a/src/commands/signal-handler.ts
+++ b/src/commands/signal-handler.ts
@@ -1,7 +1,7 @@
 /**
  * Dependencies injected into {@link registerSignalHandlers}.
  */
-export interface SignalHandlerDependencies {
+interface SignalHandlerDependencies {
   /** Returns whether containers have been started; read at signal time. */
   getContainersStarted: () => boolean;
   /** Whether to preserve containers on exit (--keep-containers flag). */