diff --git a/src/engine/execunix.c b/src/engine/execunix.c
index 8ee4d9dbf..21a223d9e 100644
--- a/src/engine/execunix.c
+++ b/src/engine/execunix.c
@@ -64,8 +64,6 @@ static int get_free_cmdtab_slot();
 /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
 
 static clock_t tps;
-static int old_time_initialized;
-static struct tms old_time;
 
 /* We hold stdout & stderr child process information in two element arrays
  * indexed as follows.
@@ -178,13 +176,6 @@ void exec_cmd
         exit( EXITBAD );
     }
 
-    /* Initialize old_time only once. */
-    if ( !old_time_initialized )
-    {
-        times( &old_time );
-        old_time_initialized = 1;
-    }
-
     /* Start the command */
 
     timestamp_current( &cmdtab[ slot ].start_dt );
@@ -513,6 +504,7 @@ void exec_wait()
                 int status;
                 int rstat;
                 timing_info time_info;
+                struct rusage cmd_usage;
 
                 /* We found a terminated child process - our search is done. */
                 finished = 1;
@@ -523,7 +515,7 @@ void exec_wait()
                     close_streams( i, ERR );
 
                 /* Reap the child and release resources. */
-                while ( ( pid = waitpid( cmdtab[ i ].pid, &status, 0 ) ) == -1 )
+                while ( ( pid = wait4( cmdtab[ i ].pid, &status, 0, &cmd_usage ) ) == -1 )
                     if ( errno != EINTR )
                         break;
                 if ( pid != cmdtab[ i ].pid )
@@ -539,15 +531,10 @@ void exec_wait()
                         : EXIT_OK;
 
                 {
-                    struct tms new_time;
-                    times( &new_time );
-                    time_info.system = (double)( new_time.tms_cstime -
-                        old_time.tms_cstime ) / CLOCKS_PER_SEC;
-                    time_info.user   = (double)( new_time.tms_cutime -
-                        old_time.tms_cutime ) / CLOCKS_PER_SEC;
+                    time_info.system = ((double)(cmd_usage.ru_stime.tv_sec)*1000000.0+(double)(cmd_usage.ru_stime.tv_usec))/1000000.0;
+                    time_info.user   = ((double)(cmd_usage.ru_utime.tv_sec)*1000000.0+(double)(cmd_usage.ru_utime.tv_usec))/1000000.0;
                     timestamp_copy( &time_info.start, &cmdtab[ i ].start_dt );
                     timestamp_current( &time_info.end );
-                    old_time = new_time;
                 }
 
                 /* Drive the completion. */
diff --git a/src/engine/make1.c b/src/engine/make1.c
index 7dbf7c8da..b7fe51728 100644
--- a/src/engine/make1.c
+++ b/src/engine/make1.c
@@ -854,7 +854,9 @@ static void make1c_closure
     {
         call_timing_rule( t, time );
         if ( DEBUG_EXECCMD )
-            out_printf( "%f sec system; %f sec user\n", time->system, time->user );
+            out_printf( "%f sec system; %f sec user, %f sec clock\n",
+                time->system, time->user,
+                timestamp_delta_seconds(&time->start, &time->end) );
 
         /* Assume -p0 is in effect, i.e. cmd_stdout contains merged output. */
         call_action_rule( t, status_orig, time, cmd->buf->value, cmd_stdout );
diff --git a/src/engine/timestamp.c b/src/engine/timestamp.c
index 17510bcd0..b6fd906ef 100644
--- a/src/engine/timestamp.c
+++ b/src/engine/timestamp.c
@@ -261,3 +261,11 @@ void timestamp_done()
         hashdone( bindhash );
     }
 }
+
+/*
+ * timestamp_delta_seconds() - seconds from time a to b.
+ */
+double timestamp_delta_seconds( timestamp const * const a , timestamp const * const b )
+{
+	return ((b->secs*1000000.0+b->nsecs)-(a->secs*1000000.0+a->nsecs))/1000000.0;
+}
diff --git a/src/engine/timestamp.h b/src/engine/timestamp.h
index ecedb5f92..e9b41753c 100644
--- a/src/engine/timestamp.h
+++ b/src/engine/timestamp.h
@@ -42,5 +42,6 @@ void timestamp_from_filetime( timestamp * const, FILETIME const * const );
 #endif
 
 void timestamp_done();
+double timestamp_delta_seconds( timestamp const * const, timestamp const * const );
 
 #endif