diff --git a/MuonSpectrometer/MuonDetDescr/MuonAGDDBase/MuonAGDDBase/ATLAS_CHECK_THREAD_SAFETY b/MuonSpectrometer/MuonDetDescr/MuonAGDDBase/MuonAGDDBase/ATLAS_CHECK_THREAD_SAFETY
new file mode 100644
index 0000000000000000000000000000000000000000..6bd22768dad151006d3a33ca8eee5fe8761946cf
--- /dev/null
+++ b/MuonSpectrometer/MuonDetDescr/MuonAGDDBase/MuonAGDDBase/ATLAS_CHECK_THREAD_SAFETY
@@ -0,0 +1 @@
+MuonSpectrometer/MuonDetDescr/MuonAGDDBase
diff --git a/MuonSpectrometer/MuonDetDescr/MuonAGDDBase/src/AGDDMuonStation.cxx b/MuonSpectrometer/MuonDetDescr/MuonAGDDBase/src/AGDDMuonStation.cxx
index b3245684b94f2ae3f650a2c30c68e6f7599c3bcf..adff8d754ad1a38d33e9251b810d2734965c4ac8 100644
--- a/MuonSpectrometer/MuonDetDescr/MuonAGDDBase/src/AGDDMuonStation.cxx
+++ b/MuonSpectrometer/MuonDetDescr/MuonAGDDBase/src/AGDDMuonStation.cxx
@@ -32,14 +32,8 @@ void AGDDMuonStation::CreateSolid (const AGDDBuilder& /*builder*/)
 void AGDDMuonStation::CreateVolume (const AGDDBuilder& builder)
 {
     std::cout<<"this is AGDDMuonStation::CreateVolume()"<<std::endl;
-	static int ifirst=1;
-	static const GeoMaterial* air=0;
-	if (ifirst)
-	{
-		ifirst=0;
-        air = GetMMMaterial("std::Air");
-		if (!air) std::cout<<" Air not found!"<<std::endl;
-	}
+	static const GeoMaterial* const air = GetMMMaterial("std::Air");
+        if (!air) std::cout<<" Air not found!"<<std::endl;
 
 	CreateSolid (builder);