diff --git a/Utilities/ReleaseScripts/scripts/addOnTests.py b/Utilities/ReleaseScripts/scripts/addOnTests.py
index b7203ddcd29f2..83372de8a95a2 100755
--- a/Utilities/ReleaseScripts/scripts/addOnTests.py
+++ b/Utilities/ReleaseScripts/scripts/addOnTests.py
@@ -145,12 +145,10 @@ def runTests(self, testList = None):
 
         print('Running in %s thread(s)' % self.maxThreads)
 
+        if testList:
+            self.commands = {d:c for d,c in self.commands.items() if d in testList}
         for dirName, command in self.commands.items():
 
-            if testList and not dirName in testList:
-                del self.commands[dirName]
-                continue
-
             # make sure we don't run more than the allowed number of threads:
             while self.activeThreads() >= self.maxThreads:
                 time.sleep(10)