diff --git a/Database/AthenaPOOL/RootFileTools/src/merge.cxx b/Database/AthenaPOOL/RootFileTools/src/merge.cxx
index 13a0366e041e649d75edaee589a9ae39ad2c847e..2afe3818d9331eba868d7e69e4469ac589daca7d 100644
--- a/Database/AthenaPOOL/RootFileTools/src/merge.cxx
+++ b/Database/AthenaPOOL/RootFileTools/src/merge.cxx
@@ -100,7 +100,7 @@ void addBranch( ::TTree* otree, ::TBranch* ibranch )
    // Get the type of the branch:
    TClass* cl = 0;
    EDataType dt = kOther_t;
-   ibranch->GetExpectedType( cl, dt );
+   (void)ibranch->GetExpectedType( cl, dt );
 	
    // Pointer to the output branch:
    ::TBranch* obranch = 0;