diff --git a/ChangeLog b/ChangeLog
index 07fb1fe78..632e1d4ce 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2002-12-10  Mikael Djurfeldt  <mdj@kvast.blakulla.net>
+
+	* configure.in (_THREAD_SAFE): Define when pthreads are enabled in
+	order to get thread safe versions of glibc functions.
+
 2002-12-09  Mikael Djurfeldt  <djurfeldt@nada.kth.se>
 
 	* configure.in: Temporarily replaced "copt" threads option with new
diff --git a/configure.in b/configure.in
index 2ed8545c8..ef66cab80 100644
--- a/configure.in
+++ b/configure.in
@@ -649,6 +649,10 @@ case "$with_threads" in
         [Define if using pthread multithreading.])
       with_threads="pthreads",
       with_threads="null")
+      if test $GCC = yes; then
+      AC_DEFINE(_THREAD_SAFE, 1,
+        [Use thread safe versions of GNU Libc functions.])
+      fi
   ;;
 esac