diff --git a/tests/boundary/filesystem/clientConfigurationDialects.test.ts b/tests/boundary/filesystem/clientConfigurationDialects.test.ts
index 609291932..71d6512ec 100644
--- a/tests/boundary/filesystem/clientConfigurationDialects.test.ts
+++ b/tests/boundary/filesystem/clientConfigurationDialects.test.ts
@@ -11,14 +11,12 @@ import { supportedClients } from "../../../src/application/SupportedClients.js";
 import { PRODUCT_IDENTITY } from "../../../src/identity.js";
 import { isOwnedClientRegistrationCommand } from "../../../src/application/ClientRegistrationIdentity.js";
 import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
-import { clearClientLocationEnvironment } from "../../fixtures/clientEnvironment.js";
+import {
+  clearClientLocationEnvironment,
+  NPX_REGISTRATION_COMMAND,
+} from "../../fixtures/clientEnvironment.js";
 
-const command = [
-  "npx",
-  "-y",
-  PRODUCT_IDENTITY.registrationPackageSpecifier,
-  "mcp",
-] as const;
+const command = NPX_REGISTRATION_COMMAND;
 
 beforeEach(clearClientLocationEnvironment);
 
diff --git a/tests/boundary/filesystem/ompClientConfiguration.test.ts b/tests/boundary/filesystem/ompClientConfiguration.test.ts
index 2815ec134..0f5aeb2cc 100644
--- a/tests/boundary/filesystem/ompClientConfiguration.test.ts
+++ b/tests/boundary/filesystem/ompClientConfiguration.test.ts
@@ -8,16 +8,13 @@ import { readClientRegistrationStatuses } from "../../../src/application/ClientR
 import { configureClientConfiguration } from "../../../src/application/SetupClientConfiguration.js";
 import { supportedClients } from "../../../src/application/SupportedClients.js";
 import { systemUninstallHost } from "../../../src/application/Uninstall.js";
-import { PRODUCT_IDENTITY } from "../../../src/identity.js";
 import { createTestTempDirectory } from "../../fixtures/temporaryDirectory.js";
-import { clearClientLocationEnvironment } from "../../fixtures/clientEnvironment.js";
+import {
+  clearClientLocationEnvironment,
+  NPX_REGISTRATION_COMMAND,
+} from "../../fixtures/clientEnvironment.js";
 
-const command = [
-  "npx",
-  "-y",
-  PRODUCT_IDENTITY.registrationPackageSpecifier,
-  "mcp",
-] as const;
+const command = NPX_REGISTRATION_COMMAND;
 
 beforeEach(clearClientLocationEnvironment);
 afterEach(() => vi.unstubAllEnvs());
diff --git a/tests/fixtures/clientEnvironment.ts b/tests/fixtures/clientEnvironment.ts
index f8657d25c..79961e49d 100644
--- a/tests/fixtures/clientEnvironment.ts
+++ b/tests/fixtures/clientEnvironment.ts
@@ -1,5 +1,15 @@
 import { vi } from "vitest";
 
+import { PRODUCT_IDENTITY } from "../../src/identity.js";
+
+/** The default npx registration command setup writes on POSIX hosts. */
+export const NPX_REGISTRATION_COMMAND = [
+  "npx",
+  "-y",
+  PRODUCT_IDENTITY.registrationPackageSpecifier,
+  "mcp",
+] as const;
+
 /** Environment variables that redirect where supported clients keep config. */
 export const CLIENT_LOCATION_ENVIRONMENT = [
   "APPDATA",