diff --git a/Sources/IoT-Simulator-Core/Factories/DeviceFactories.swift b/Sources/IoT-Simulator-Core/Factories/DeviceFactories.swift
index e91800a..3ad4549 100644
--- a/Sources/IoT-Simulator-Core/Factories/DeviceFactories.swift
+++ b/Sources/IoT-Simulator-Core/Factories/DeviceFactories.swift
@@ -92,7 +92,7 @@ public actor DeviceFactory {
             throw CoreError.FinishedIDs
         }
 
-        return DeviceFactory.availableIDs.removeFirst()
+        return DeviceFactory.availableIDs.first!
     }
 
 }