diff --git a/cpp/clock/clock.cpp b/cpp/clock/clock.cpp
index 8f34e4e..b08ad25 100644
--- a/cpp/clock/clock.cpp
+++ b/cpp/clock/clock.cpp
@@ -10,12 +10,12 @@ const minutes_t minutes_per_hour = 60;
 const hours_t   hours_per_day    = 24;
 const total_t   minutes_per_day  = hours_per_day * minutes_per_hour;
 
-inline void make_date_independent(total_t total_minutes)
+inline void wrap_midnight(total_t &total_minutes)
 {
-    while (total_minutes < 0)
-        total_minutes += minutes_per_day;
+    total_minutes %= minutes_per_day;
 
-    total_minutes = total_minutes % minutes_per_day;
+    if (total_minutes < 0)
+        total_minutes += minutes_per_day;
 }
 
 }
@@ -24,7 +24,7 @@ inline void make_date_independent(total_t total_minutes)
 clock::clock(hours_t hours, minutes_t minutes)
 {
     total_minutes_ = minutes_per_hour*hours + minutes;
-    make_date_independent(total_minutes_);
+    wrap_midnight(total_minutes_);
 }
 
 bool clock::operator==(const clock &other) const
@@ -47,7 +47,7 @@ clock clock::plus(minutes_t minutes) const
     clock result(*this);
 
     result.total_minutes_ += minutes;
-    make_date_independent(result.total_minutes_);
+    wrap_midnight(result.total_minutes_);
 
     return result;
 }
@@ -59,7 +59,7 @@ clock clock::minus(minutes_t minutes) const
 
 clock::operator std::string() const
 {
-    minutes_t minutes = total_minutes_ % minutes_per_hour
+    minutes_t minutes = total_minutes_ % minutes_per_hour;
     hours_t   hours   = total_minutes_ / minutes_per_hour;
 
     char buff[6];