diff --git a/src/timed_thread.c b/src/timed_thread.c
index c6c5a781..81f481e5 100644
--- a/src/timed_thread.c
+++ b/src/timed_thread.c
@@ -25,7 +25,6 @@
 #include <pthread.h>
 #include <assert.h>
 #include <errno.h>
-#include <math.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <time.h>
@@ -110,10 +109,11 @@ timed_thread_create (void *(*start_routine)(void*), void *arg, unsigned int inte
   /* remaining microseconds convert to nanoseconds */
   p_timed_thread->interval_time.tv_nsec = (long)((interval_usecs % 1000000) * 1000);
 
-  /*printf ("interval_time.tv_sec = %li, .tv_nsec = %li\n",
+  /*
+  printf ("interval_time.tv_sec = %li, .tv_nsec = %li\n",
             p_timed_thread->interval_time.tv_sec,
-            p_timed_thread->interval_time.tv_nsec);*/
-
+            p_timed_thread->interval_time.tv_nsec);
+  */
   return p_timed_thread;
 }
 
@@ -186,17 +186,18 @@ timed_thread_test (timed_thread* p_timed_thread)
 
   if (now (&wait_time)) return (-1);
   /*printf ("PRE:wait_time.tv_secs = %li, .tv_nsecs = %li\n", wait_time.tv_sec, wait_time.tv_nsec);*/
-  /* now add in the wait interval */
-  if (1000000000-wait_time.tv_nsec < p_timed_thread->interval_time.tv_nsec)
+ 
+  /* add in the wait interval */
+  if (1000000000-wait_time.tv_nsec <= p_timed_thread->interval_time.tv_nsec)
   {
     /* adjust for impending overflow of wait_time.tv_nsec */
-    wait_time.tv_sec += p_timed_thread->interval_time.tv_sec;
-    wait_time.tv_sec += (p_timed_thread->interval_time.tv_nsec / 1000000000) + 1;
-    wait_time.tv_nsec = labs (wait_time.tv_nsec - p_timed_thread->interval_time.tv_nsec);
+    wait_time.tv_sec += p_timed_thread->interval_time.tv_sec + 1;
+    wait_time.tv_nsec = wait_time.tv_nsec - (1000000000 - p_timed_thread->interval_time.tv_nsec);
     /*printf ("001:wait_time.tv_secs = %li, .tv_nsecs = %li\n", wait_time.tv_sec, wait_time.tv_nsec);*/
   }
   else
   {
+    /* no overflow will occur, just add respective components */
     wait_time.tv_sec += p_timed_thread->interval_time.tv_sec;
     wait_time.tv_nsec += p_timed_thread->interval_time.tv_nsec;
     /*printf ("002:wait_time.tv_secs = %li, .tv_nsecs = %li\n", wait_time.tv_sec, wait_time.tv_nsec);*/