--- callgrind/main.c.orig
+++ callgrind/main.c
@@ -1726,7 +1726,8 @@
       break;
     }
    case systime_nsec:
-#  if defined(VGO_linux) || defined(VGO_solaris) || defined(VGO_freebsd)
+#  if defined(VGO_linux) || defined(VGO_solaris) || defined(VGO_freebsd) || \
+      defined(VGO_openbsd)
       VG_(clock_gettime)(systime, VKI_CLOCK_MONOTONIC);
       VG_(clock_gettime)(syscputime, VKI_CLOCK_THREAD_CPUTIME_ID);