diff --git a/src/app/api/machines/session/route.ts b/src/app/api/machines/session/route.ts
index 5655b5a..d2cb7c0 100644
--- a/src/app/api/machines/session/route.ts
+++ b/src/app/api/machines/session/route.ts
@@ -93,13 +93,16 @@ export async function GET(request: NextRequest) {
     let ensuredAssignedUserName = context.assignedUserName
     let ensuredAssignedUserRole = context.assignedUserRole
 
-    if (!ensuredAssignedUserId && context.persona && context.assignedUserEmail) {
+    if (!ensuredAssignedUserId && context.assignedUserEmail) {
       try {
+        const personaRole = (context.persona ?? context.assignedUserRole ?? "collaborator").toString().toLowerCase()
+        const normalizedPersona = personaRole && typeof personaRole === "string" ? personaRole : "collaborator"
+
         const ensuredUser = (await client.mutation(api.users.ensureUser, {
           tenantId: context.tenantId ?? DEFAULT_TENANT_ID,
           email: context.assignedUserEmail,
           name: context.assignedUserName ?? context.assignedUserEmail,
-          role: (context.assignedUserRole ?? context.persona ?? "collaborator").toUpperCase(),
+          role: normalizedPersona.toUpperCase(),
           companyId: context.companyId ? (context.companyId as Id<"companies">) : undefined,
         })) as {
           _id?: Id<"users">
@@ -114,7 +117,7 @@ export async function GET(request: NextRequest) {
 
           await client.mutation(api.machines.updatePersona, {
             machineId: machineId as Id<"machines">,
-            persona: context.persona ?? undefined,
+            persona: normalizedPersona,
             assignedUserId: ensuredUser._id as Id<"users">,
             assignedUserEmail: context.assignedUserEmail,
             assignedUserName: ensuredAssignedUserName ?? undefined,
@@ -136,7 +139,7 @@ export async function GET(request: NextRequest) {
 
     const responsePayload = {
       machineId: context.id,
-      persona: context.persona,
+      persona: context.persona ?? (ensuredAssignedUserRole ? ensuredAssignedUserRole.toLowerCase() : null),
       assignedUserId: ensuredAssignedUserId,
       assignedUserEmail: context.assignedUserEmail,
       assignedUserName: ensuredAssignedUserName,