diff --git a/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H b/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
index 826bb95741..0e13b7c9a1 100644
--- a/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
+++ b/src/OpenFOAM/containers/HashTables/HashTable/HashTable.H
@@ -330,6 +330,9 @@ public:
                 inline T& operator*();
                 inline T& operator()();
 
+                inline const T& operator*() const;
+                inline const T& operator()() const;
+
                 inline iterator& operator++();
                 inline iterator operator++(int);
 
@@ -389,8 +392,8 @@ public:
                 inline bool operator==(const iterator&) const;
                 inline bool operator!=(const iterator&) const;
 
-                inline const T& operator*();
-                inline const T& operator()();
+                inline const T& operator*() const;
+                inline const T& operator()() const;
 
                 inline const_iterator& operator++();
                 inline const_iterator operator++(int);
diff --git a/src/OpenFOAM/containers/HashTables/HashTable/HashTableI.H b/src/OpenFOAM/containers/HashTables/HashTable/HashTableI.H
index 005979df3f..e2655da433 100644
--- a/src/OpenFOAM/containers/HashTables/HashTable/HashTableI.H
+++ b/src/OpenFOAM/containers/HashTables/HashTable/HashTableI.H
@@ -220,16 +220,34 @@ inline bool Foam::HashTable<T, Key, Hash>::iterator::operator!=
 
 
 template<class T, class Key, class Hash>
-inline T& Foam::HashTable<T, Key, Hash>::iterator::operator*()
+inline T&
+Foam::HashTable<T, Key, Hash>::iterator::operator*()
 {
     return elmtPtr_->obj_;
 }
 
 
 template<class T, class Key, class Hash>
-inline T& Foam::HashTable<T, Key, Hash>::iterator::operator()()
+inline T&
+Foam::HashTable<T, Key, Hash>::iterator::operator()()
 {
-    return operator*();
+    return elmtPtr_->obj_;
+}
+
+
+template<class T, class Key, class Hash>
+inline const T&
+Foam::HashTable<T, Key, Hash>::iterator::operator*() const
+{
+    return elmtPtr_->obj_;
+}
+
+
+template<class T, class Key, class Hash>
+inline const T&
+Foam::HashTable<T, Key, Hash>::iterator::operator()() const
+{
+    return elmtPtr_->obj_;
 }
 
 
@@ -410,16 +428,18 @@ inline bool Foam::HashTable<T, Key, Hash>::const_iterator::operator!=
 
 
 template<class T, class Key, class Hash>
-inline const T& Foam::HashTable<T, Key, Hash>::const_iterator::operator*()
+inline const T& 
+Foam::HashTable<T, Key, Hash>::const_iterator::operator*() const
 {
     return elmtPtr_->obj_;
 }
 
 #ifndef __CINT__
 template<class T, class Key, class Hash>
-inline const T& Foam::HashTable<T, Key, Hash>::const_iterator::operator()()
+inline const T&
+Foam::HashTable<T, Key, Hash>::const_iterator::operator()() const
 {
-    return operator*();
+    return elmtPtr_->obj_;
 }
 #endif