diff --git a/MuonSpectrometer/MuonIdHelpers/MuonIdHelpers/MmIdHelper.h b/MuonSpectrometer/MuonIdHelpers/MuonIdHelpers/MmIdHelper.h
index 1d555217e6640ec1f3dd5c3988ea7a270ab103ce..ef5ed5e4f3be130ec91fbe4dd3e923d7bf1339e7 100644
--- a/MuonSpectrometer/MuonIdHelpers/MuonIdHelpers/MmIdHelper.h
+++ b/MuonSpectrometer/MuonIdHelpers/MuonIdHelpers/MmIdHelper.h
@@ -93,7 +93,7 @@ class MmIdHelper : public MuonIdHelper {
   int gasGap(const Identifier& id) const;
   int multilayer(const Identifier& id) const;
   int channel(const Identifier& id) const;
-  bool measuresPhi(const Identifier& id) const; //Returns false
+  bool measuresPhi(const Identifier& id) const; //Returns true for stereo layers
 
   int numberOfMultilayers(const Identifier& id) const;
 
@@ -302,8 +302,12 @@ inline int MmIdHelper::gasGapMin() const {
   return GasGapMin;
 }
 /*******************************************************************************/ 
-inline bool MmIdHelper::measuresPhi(const Identifier& /*id*/) const{
-  return false; 
+inline bool MmIdHelper::measuresPhi(const Identifier& id) const{
+  bool measPhi = false;
+  int ml = multilayer(id);
+  int gg = gasGap(id);
+  if ( (ml==1 && gg>2) || (ml==2 && gg<3) ) measPhi = true;
+  return measPhi;                                                                                               
 }
 /*******************************************************************************/ 
 inline int MmIdHelper::gasGapMax() const {