diff --git a/agent/protect.c b/agent/protect.c
--- a/agent/protect.c
+++ b/agent/protect.c
@@ -23,6 +23,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <time.h>
 #include <ctype.h>
 #include <assert.h>
 #include <unistd.h>
@@ -76,7 +77,7 @@
 #ifdef HAVE_W32_SYSTEM
   FILETIME creation_time, exit_time, kernel_time, user_time;
 #else
-  clock_t ticks;
+  unsigned long ms;
 #endif
 };
 
@@ -104,11 +105,24 @@
                    &data->creation_time, &data->exit_time,
                    &data->kernel_time, &data->user_time);
 # endif
+#elif defined (CLOCK_THREAD_CPUTIME_ID)
+  struct timespec tmp;
+
+  clock_gettime (CLOCK_THREAD_CPUTIME_ID, &tmp);
+  /* Convert from seconds + nanoseconds to milliseconds. */
+  data->ms = (unsigned long)((tmp.tv_sec * 1000000000 + tmp.tv_nsec)
+			     / 1000000.0);
 #else
   struct tms tmp;
+  static long ticks_per_second;
+
+  if (!ticks_per_second)
+    ticks_per_second = sysconf (_SC_CLK_TCK);
 
   times (&tmp);
-  data->ticks = tmp.tms_utime;
+  /* Convert from clock ticks to milliseconds. */
+  data->ms = (unsigned long)((tmp.tms_utime / (double)ticks_per_second)
+			     * 1000);
 #endif
 }
 
@@ -134,8 +148,7 @@
     return (unsigned long)((t2 - t1)/10000);
   }
 #else
-  return (unsigned long)((((double) (stoptime.ticks - starttime->ticks))
-                          /CLOCKS_PER_SEC)*10000000);
+  return stoptime.ms - starttime->ms;
 #endif
 }