diff --git a/src/python/CRABClient/JobType/CMSSWConfig.py b/src/python/CRABClient/JobType/CMSSWConfig.py
index b2a9e821..9822d8be 100644
--- a/src/python/CRABClient/JobType/CMSSWConfig.py
+++ b/src/python/CRABClient/JobType/CMSSWConfig.py
@@ -277,6 +277,7 @@ def validateConfig(self):
             msg = "The only accepted type for process.options.numberOfThreads is uint32. Please, change its type in the PSet."
             msg += "See https://github.com/cms-sw/cmssw/issues/32070 for details"
             return False, msg
+        numPSetCores = numPSetCores.value()  # convert to python native type (int) #5323
         if (cfgNumCores or 1) != (numPSetCores or 1):
             if cfgNumCores == None:
                 msg = "You did not set config.JobType.numCores in the crab configuration file "