diff --git a/actions/setup/js/check_membership.cjs b/actions/setup/js/check_membership.cjs
index 699d38bb419..49103a93e6b 100644
--- a/actions/setup/js/check_membership.cjs
+++ b/actions/setup/js/check_membership.cjs
@@ -52,19 +52,14 @@ async function main() {
   // Check if the actor has the required repository permissions
   const result = await checkRepositoryPermission(actor, owner, repo, requiredPermissions);
 
-  if (result.error) {
-    core.setOutput("is_team_member", "false");
-    core.setOutput("result", "api_error");
-    core.setOutput("error_message", `Repository permission check failed: ${result.error}`);
-    return;
-  }
-
   if (result.authorized) {
     core.setOutput("is_team_member", "true");
     core.setOutput("result", "authorized");
     core.setOutput("user_permission", result.permission);
   } else {
-    // User doesn't have required permissions, check if they're an allowed bot
+    // User doesn't have required permissions (or the permission check failed with an error).
+    // Always attempt the bot allowlist fallback before giving up, so that GitHub Apps whose
+    // actor is not a recognized GitHub user (e.g. "Copilot") are not silently denied.
     if (allowedBots && allowedBots.length > 0) {
       core.info(`Checking if actor '${actor}' is in allowed bots list: ${allowedBots.join(", ")}`);
 
@@ -84,7 +79,7 @@ async function main() {
           core.warning(`Bot '${actor}' is in the allowed list but not active/installed on ${owner}/${repo}`);
           core.setOutput("is_team_member", "false");
           core.setOutput("result", "bot_not_active");
-          core.setOutput("user_permission", result.permission);
+          core.setOutput("user_permission", result.permission ?? "bot");
           core.setOutput("error_message", `Access denied: Bot '${actor}' is not active/installed on this repository`);
           return;
         } else {
@@ -94,14 +89,20 @@ async function main() {
     }
 
     // Not authorized by role or bot
-    core.setOutput("is_team_member", "false");
-    core.setOutput("result", "insufficient_permissions");
-    core.setOutput("user_permission", result.permission);
-    core.setOutput(
-      "error_message",
-      `Access denied: User '${actor}' is not authorized. Required permissions: ${requiredPermissions.join(", ")}. ` +
-        `To allow this user to run the workflow, add their role to the frontmatter. Example: roles: [${requiredPermissions.join(", ")}, ${result.permission}]`
-    );
+    if (result.error) {
+      core.setOutput("is_team_member", "false");
+      core.setOutput("result", "api_error");
+      core.setOutput("error_message", `Repository permission check failed: ${result.error}`);
+    } else {
+      core.setOutput("is_team_member", "false");
+      core.setOutput("result", "insufficient_permissions");
+      core.setOutput("user_permission", result.permission);
+      core.setOutput(
+        "error_message",
+        `Access denied: User '${actor}' is not authorized. Required permissions: ${requiredPermissions.join(", ")}. ` +
+          `To allow this user to run the workflow, add their role to the frontmatter. Example: roles: [${requiredPermissions.join(", ")}, ${result.permission}]`
+      );
+    }
   }
 }
 
diff --git a/actions/setup/js/check_membership.test.cjs b/actions/setup/js/check_membership.test.cjs
index 81d61457d3b..9cd490489f5 100644
--- a/actions/setup/js/check_membership.test.cjs
+++ b/actions/setup/js/check_membership.test.cjs
@@ -381,6 +381,51 @@ describe("check_membership.cjs", () => {
       expect(mockCore.setOutput).toHaveBeenCalledWith("result", "insufficient_permissions");
     });
 
+    it("should authorize a bot in the allowlist when permission check returns an API error (e.g. GitHub App not a user)", async () => {
+      process.env.GH_AW_ALLOWED_BOTS = "Copilot";
+      mockContext.actor = "Copilot";
+
+      const notAUserError = new Error("Copilot is not a user");
+      mockGithub.rest.repos.getCollaboratorPermissionLevel
+        .mockRejectedValueOnce(notAUserError) // initial permission check → error
+        .mockResolvedValueOnce({ data: { permission: "none" } }); // bot status check (Copilot[bot] form) → active
+
+      await runScript();
+
+      expect(mockCore.setOutput).toHaveBeenCalledWith("is_team_member", "true");
+      expect(mockCore.setOutput).toHaveBeenCalledWith("result", "authorized_bot");
+      expect(mockCore.setOutput).toHaveBeenCalledWith("user_permission", "bot");
+    });
+
+    it("should return bot_not_active when permission check returns API error and bot is not installed", async () => {
+      process.env.GH_AW_ALLOWED_BOTS = "Copilot";
+      mockContext.actor = "Copilot";
+
+      const notAUserError = new Error("Copilot is not a user");
+      const notFoundError = { status: 404, message: "Not Found" };
+      mockGithub.rest.repos.getCollaboratorPermissionLevel
+        .mockRejectedValueOnce(notAUserError) // initial permission check → error
+        .mockRejectedValue(notFoundError); // all bot status checks → 404
+
+      await runScript();
+
+      expect(mockCore.setOutput).toHaveBeenCalledWith("is_team_member", "false");
+      expect(mockCore.setOutput).toHaveBeenCalledWith("result", "bot_not_active");
+    });
+
+    it("should return api_error when permission check fails and actor is not in allowed bots list", async () => {
+      process.env.GH_AW_ALLOWED_BOTS = "some-other-bot";
+      mockContext.actor = "Copilot";
+
+      const notAUserError = new Error("Copilot is not a user");
+      mockGithub.rest.repos.getCollaboratorPermissionLevel.mockRejectedValue(notAUserError);
+
+      await runScript();
+
+      expect(mockCore.setOutput).toHaveBeenCalledWith("is_team_member", "false");
+      expect(mockCore.setOutput).toHaveBeenCalledWith("result", "api_error");
+    });
+
     it("should authorize a bot with [bot] suffix in the allowlist via slug fallback", async () => {
       process.env.GH_AW_ALLOWED_BOTS = "copilot";
       mockContext.actor = "copilot[bot]";