diff --git a/reco/L1/L1Algo/L1Algo.cxx b/reco/L1/L1Algo/L1Algo.cxx
index 323a5bff730a4f9a36fedfca2324e1d0fed4335f..2aacf0a3cb5092df8654bc6252efd0fd5f51942a 100644
--- a/reco/L1/L1Algo/L1Algo.cxx
+++ b/reco/L1/L1Algo/L1Algo.cxx
@@ -17,8 +17,9 @@ L1Algo::L1Algo(unsigned int nThreads)
 
 void L1Algo::SetNThreads(unsigned int n)
 {
-  if (n > fkMaxNthreads) {
-    LOG(FATAL) << "L1Algo: n threads " << n << " is greater than the maximum " << fkMaxNthreads << std::endl;
+  if (n > static_cast<unsigned int>(fkMaxNthreads)) {
+    LOG(fatal) << "L1Algo: n threads " << n << " is greater than the maximum "
+               << static_cast<unsigned int>(fkMaxNthreads) << std::endl;
   }
   fNThreads = n;