diff --git a/k4Interface/include/k4Interface/INoiseCaloCellsTool.h b/k4Interface/include/k4Interface/INoiseCaloCellsTool.h
index 074846cf..59c59b15 100644
--- a/k4Interface/include/k4Interface/INoiseCaloCellsTool.h
+++ b/k4Interface/include/k4Interface/INoiseCaloCellsTool.h
@@ -34,8 +34,11 @@ class INoiseCaloCellsTool : virtual public IAlgTool {
 public:
   DeclareInterfaceID(INoiseCaloCellsTool, 1, 0);
 
-  virtual void addRandomCellNoise(std::unordered_map<uint64_t, double>& aCells) = 0;
-  virtual void filterCellNoise(std::unordered_map<uint64_t, double>& aCells) = 0;
+  virtual void addRandomCellNoise(std::unordered_map<uint64_t, double>& aCells) const = 0;
+  virtual void filterCellNoise(std::unordered_map<uint64_t, double>& aCells) const = 0;
+
+  virtual void addRandomCellNoise(std::vector<std::pair<uint64_t, double>>& aCells) const = 0;
+  virtual void filterCellNoise(std::vector<std::pair<uint64_t, double>>& aCells) const = 0;
 };
 
 #endif /* RECINTERFACE_INOISECALOCELLSTOOL_H */
diff --git a/k4Interface/include/k4Interface/INoiseConstTool.h b/k4Interface/include/k4Interface/INoiseConstTool.h
index 9b17c3de..7e518666 100644
--- a/k4Interface/include/k4Interface/INoiseConstTool.h
+++ b/k4Interface/include/k4Interface/INoiseConstTool.h
@@ -33,8 +33,8 @@ class INoiseConstTool : virtual public IAlgTool {
 public:
   DeclareInterfaceID(INoiseConstTool, 1, 0);
 
-  virtual double getNoiseRMSPerCell(uint64_t aCellID) = 0;
-  virtual double getNoiseOffsetPerCell(uint64_t aCellID) = 0;
+  virtual double getNoiseRMSPerCell(uint64_t aCellID) const = 0;
+  virtual double getNoiseOffsetPerCell(uint64_t aCellID) const = 0;
 };
 
 #endif /* RECINTERFACE_INOISECONSTTOOL_H */