diff --git a/boehm-gc/ChangeLog b/boehm-gc/ChangeLog
index f9f4b9e88fa97a760a8ef5e0f018cd66770f1520..47a7e7bdeddb80acc72162127628c6bdb227ed12 100644
--- a/boehm-gc/ChangeLog
+++ b/boehm-gc/ChangeLog
@@ -1,5 +1,8 @@
 2000-07-24  Alexandre Oliva  <aoliva@redhat.com>
 
+	* configure.in (THREADS): Don't --enable-threads on IRIX <= 5.*.
+	* configure: Rebuilt.
+
 	* dyn_load.c (GC_scratch_last_end_ptr): Don't declare a #define.
 
 2000-06-20  Bryce McKinlay  <bryce@albatross.co.nz>
diff --git a/boehm-gc/configure b/boehm-gc/configure
index 5f3ab6553301cd496609b3f91fadbe563378e1a6..95e7184b90ce24566dfa4fd01c6a76d973561835 100755
--- a/boehm-gc/configure
+++ b/boehm-gc/configure
@@ -2072,6 +2072,10 @@ if test "$THREADS" = yes; then
     *-*-win*)
        THREADS=win32
        ;;
+    *-*-irix[1-5].*)
+       # No built-in threads library on IRIX 5.* and older.
+       THREADS=none
+       ;;
     *-*-irix*)
        # FIXME: for now, choose POSIX, because we implement that.
        # Later, choose irix threads.
diff --git a/boehm-gc/configure.in b/boehm-gc/configure.in
index 5d5e25d03334d703b63bc6c94a47ce3402dce8bd..f11cec8a33ab075d32287a6833a1013aea2a0c2f 100644
--- a/boehm-gc/configure.in
+++ b/boehm-gc/configure.in
@@ -44,6 +44,10 @@ if test "$THREADS" = yes; then
     *-*-win*)
        THREADS=win32
        ;;
+    *-*-irix[[1-5]].*)
+       # No built-in threads library on IRIX 5.* and older.
+       THREADS=none
+       ;;
     *-*-irix*)
        # FIXME: for now, choose POSIX, because we implement that.
        # Later, choose irix threads.