diff --git a/test/stressHistogram.cxx b/test/stressHistogram.cxx
index 04e39fdae11538ddcb2cdb2cf4060a6f63476f98..d95c1b1c1fd127b5eee9fec57086e6a3e940fd5d 100644
--- a/test/stressHistogram.cxx
+++ b/test/stressHistogram.cxx
@@ -118,7 +118,7 @@ enum compareOptions {
 int defaultEqualOptions = 0; //cmpOptPrint;
 //int defaultEqualOptions = cmpOptDebug;
 
-Bool_t cleanHistos = kTRUE;   // delete histogram after testing (swict off in case of debugging)
+constexpr Bool_t cleanHistos = kTRUE;   // delete histogram after testing (swicth off in case of debugging)
 
 const double defaultErrorLimit = 1.E-10;