diff --git a/src/application/SupportedClients.ts b/src/application/SupportedClients.ts
index 241c36f18f..d23f1d9ca5 100644
--- a/src/application/SupportedClients.ts
+++ b/src/application/SupportedClients.ts
@@ -360,7 +360,7 @@ const piAgentDirectory = ({
 };
 
 const copilotDirectory = ({ home, env }: ClientPathContext): string =>
-  env.COPILOT_HOME ?? join(home, ".copilot");
+  env.COPILOT_HOME || join(home, ".copilot");
 
 const commandCodeDirectory = ({ home }: ClientPathContext): string =>
   join(home, ".commandcode");
diff --git a/tests/boundary/cli/clientProfileLifecycle.test.ts b/tests/boundary/cli/clientProfileLifecycle.test.ts
index 4f684e7a8f..cb32d9964e 100644
--- a/tests/boundary/cli/clientProfileLifecycle.test.ts
+++ b/tests/boundary/cli/clientProfileLifecycle.test.ts
@@ -122,6 +122,12 @@ const cases = [
     config: ".grok/config.toml",
     skill: ".agents/skills",
   },
+  {
+    client: "copilot_cli",
+    env: { COPILOT_HOME: "" },
+    config: ".copilot/mcp-config.json",
+    skill: ".agents/skills",
+  },
   {
     client: "omp",
     env: { PI_CODING_AGENT_DIR: "profile" },