diff --git a/Configuration/Applications/python/ConfigBuilder.py b/Configuration/Applications/python/ConfigBuilder.py
index 5cfa3530d8d6b..c2eeec132e969 100644
--- a/Configuration/Applications/python/ConfigBuilder.py
+++ b/Configuration/Applications/python/ConfigBuilder.py
@@ -2263,7 +2263,7 @@ def prepare(self, doChecking = False):
         self.pythonCfgCode+="from PhysicsTools.PatAlgos.tools.helpers import associatePatAlgosToolsTask\n"
         self.pythonCfgCode+="associatePatAlgosToolsTask(process)\n"
 
-        if self._options.nThreads is not "1":
+        if self._options.nThreads != "1":
             self.pythonCfgCode +="\n"
             self.pythonCfgCode +="#Setup FWK for multithreaded\n"
             self.pythonCfgCode +="process.options.numberOfThreads = "+self._options.nThreads+"\n"