diff --git a/export_shared_agents.js b/export_shared_agents.js
index 2c47e55..b1fb709 100755
--- a/export_shared_agents.js
+++ b/export_shared_agents.js
@@ -110,7 +110,13 @@ const pipeline = [
       "agentDetails.usage_timeline": "$usageTimeline",
       "agentDetails.usage_summary": {
         conversation_count: { $ifNull: ["$usageSummary.conversationCount", 0] },
-        unique_users: { $ifNull: [{ $size: "$usageSummary.uniqueUsers" }, 0] },
+        unique_users: {
+          $cond: {
+            if: { $isArray: "$usageSummary.uniqueUsers" },
+            then: { $size: "$usageSummary.uniqueUsers" },
+            else: 0
+          }
+        },
         total_messages: { $ifNull: ["$usageSummary.totalMessages", 0] },
         first_used: "$usageSummary.firstUsed",
         last_used: "$usageSummary.lastUsed"