diff --git a/src/c++/clock.cpp b/src/c++/clock.cpp
index ab502a06..3b421f51 100644
--- a/src/c++/clock.cpp
+++ b/src/c++/clock.cpp
@@ -1,6 +1,6 @@
 #include "clock.h"
 
-Clock::time_point_t Clock::now()
+Clock::timepoint_t Clock::now()
 {
     return std::chrono::steady_clock::now();
 }
\ No newline at end of file
diff --git a/src/c++/clock.h b/src/c++/clock.h
index 61c6575c..e27d1217 100644
--- a/src/c++/clock.h
+++ b/src/c++/clock.h
@@ -6,16 +6,18 @@ class Clock{
 
       Clock() = delete;
 
-      // Type definitions for chrono steady clock time points and durations
-      using time_duration_t = std::chrono::duration<double>;
-      using time_point_t    = std::chrono::time_point<std::chrono::steady_clock, time_duration_t>;
-
     private:
 
+      // Type definitions for chrono steady clock time points and durations
+      using duration_t  = std::chrono::duration<double>;
+      using timepoint_t = std::chrono::time_point<std::chrono::steady_clock, duration_t>;
+
       // Member functions
-      static time_point_t now();
+      static timepoint_t now();
 
-      // Makes sure Clock::now() is only usable by Profiler and is otherwise 
-      // private.
-      friend class Profiler;
+      // Makes sure Clock::now() and the type definitions are only usable by 
+      // its friend classes
+      friend class  Profiler;
+      friend class  HashTable;
+      friend struct HashEntry;
 };
\ No newline at end of file
diff --git a/src/c++/hashtable.cpp b/src/c++/hashtable.cpp
index 9f8cd0b5..13d61d59 100644
--- a/src/c++/hashtable.cpp
+++ b/src/c++/hashtable.cpp
@@ -18,9 +18,9 @@
 
 HashEntry::HashEntry(std::string_view region_name)
       : region_name_(region_name)
-      , total_walltime_(Clock::time_duration_t::zero())
-      , self_walltime_(Clock::time_duration_t::zero())
-      , child_walltime_(Clock::time_duration_t::zero())
+      , total_walltime_(Clock::duration_t::zero())
+      , self_walltime_(Clock::duration_t::zero())
+      , child_walltime_(Clock::duration_t::zero())
       , call_count_(0)
       {}
 
@@ -55,7 +55,7 @@ size_t HashTable::query_insert(std::string_view region_name) noexcept
  *
  */
 
-void HashTable::update(size_t hash, Clock::time_duration_t time_delta)
+void HashTable::update(size_t hash, Clock::duration_t time_delta)
 {
   // Assertions
   assert (table_.size() > 0);
@@ -74,7 +74,7 @@ void HashTable::update(size_t hash, Clock::time_duration_t time_delta)
  *
  */
 
-void HashTable::add_child_time(size_t hash, Clock::time_duration_t time_delta)
+void HashTable::add_child_time(size_t hash, Clock::duration_t time_delta)
 {
   // Assertions
   assert (table_.size() > 0);
diff --git a/src/c++/hashtable.h b/src/c++/hashtable.h
index 63bf1ec3..eec3e880 100644
--- a/src/c++/hashtable.h
+++ b/src/c++/hashtable.h
@@ -47,9 +47,9 @@ struct HashEntry{
 
     // Data members
     std::string            region_name_;
-    Clock::time_duration_t        total_walltime_;
-    Clock::time_duration_t        self_walltime_;
-    Clock::time_duration_t        child_walltime_;
+    Clock::duration_t      total_walltime_;
+    Clock::duration_t      self_walltime_;
+    Clock::duration_t      child_walltime_;
     unsigned long long int call_count_;
 
 };
@@ -80,12 +80,12 @@ class HashTable{
 
     // Prototypes
     size_t query_insert(std::string_view) noexcept;
-    void update(size_t, Clock::time_duration_t);
+    void update(size_t, Clock::duration_t);
     void write();
 
     // Member functions
     std::vector<size_t> list_keys();
-    void add_child_time(size_t, Clock::time_duration_t);
+    void add_child_time(size_t, Clock::duration_t);
     void compute_self_times();
 
     // Getters
diff --git a/src/c++/profiler.cpp b/src/c++/profiler.cpp
index 46c5ee2c..6b5d5a1f 100644
--- a/src/c++/profiler.cpp
+++ b/src/c++/profiler.cpp
@@ -29,7 +29,7 @@ Profiler::Profiler(){
     HashTable new_table(tid);
     thread_hashtables_.push_back(new_table);
 
-    std::vector<std::pair<size_t,Clock::time_point_t>> new_list;
+    std::vector<std::pair<size_t,Clock::timepoint_t>> new_list;
     thread_traceback_.push_back(new_list);
   }
 
diff --git a/src/c++/profiler.h b/src/c++/profiler.h
index 96624d72..f095d4c7 100644
--- a/src/c++/profiler.h
+++ b/src/c++/profiler.h
@@ -39,11 +39,11 @@ class Profiler
     // Data members
     int max_threads_;
     std::vector<HashTable> thread_hashtables_;
-    std::vector<std::vector<std::pair<size_t,Clock::time_point_t>>> thread_traceback_;
+    std::vector<std::vector<std::pair<size_t,Clock::timepoint_t>>> thread_traceback_;
 
     // Type definitions for vector array indexing.
     typedef std::vector<HashTable>::size_type hashtable_iterator_t_;
-    typedef std::vector<std::vector<std::pair<size_t,Clock::time_point_t>>>::size_type pair_iterator_t_;
+    typedef std::vector<std::vector<std::pair<size_t,Clock::timepoint_t>>>::size_type pair_iterator_t_;
 
   public: