Index: otherlibs/unix/gmtime.c
===================================================================
--- otherlibs/unix/gmtime.c	(revision 10890)
+++ otherlibs/unix/gmtime.c	(working copy)
@@ -41,8 +41,9 @@
 {
   time_t clock;
   struct tm * tm;
+  struct tm tm_store;
   clock = (time_t) Double_val(t);
-  tm = gmtime(&clock);
+  tm = gmtime_r(&clock, &tm_store);
   if (tm == NULL) unix_error(EINVAL, "gmtime", Nothing);
   return alloc_tm(tm);
 }
@@ -51,8 +52,9 @@
 {
   time_t clock;
   struct tm * tm;
+  struct tm tm_store;
   clock = (time_t) Double_val(t);
-  tm = localtime(&clock);
+  tm = localtime_r(&clock,&tm_store);
   if (tm == NULL) unix_error(EINVAL, "localtime", Nothing);
   return alloc_tm(tm);
 }