diff --git a/owrx/cpu.py b/owrx/cpu.py
index 28c9066..9405b8f 100644
--- a/owrx/cpu.py
+++ b/owrx/cpu.py
@@ -7,11 +7,13 @@ logger = logging.getLogger(__name__)
 
 class CpuUsageThread(threading.Thread):
     sharedInstance = None
+    creationLock = threading.Lock()
 
     @staticmethod
     def getSharedInstance():
-        if CpuUsageThread.sharedInstance is None:
-            CpuUsageThread.sharedInstance = CpuUsageThread()
+        with CpuUsageThread.creationLock:
+            if CpuUsageThread.sharedInstance is None:
+                CpuUsageThread.sharedInstance = CpuUsageThread()
         return CpuUsageThread.sharedInstance
 
     def __init__(self):