diff --git a/boehm-gc/ChangeLog b/boehm-gc/ChangeLog
index 6fa1406bd143..a5e872814502 100644
--- a/boehm-gc/ChangeLog
+++ b/boehm-gc/ChangeLog
@@ -1,3 +1,8 @@
+2005-05-25  Andrew Haley  <aph@redhat.com>
+
+	* include/private/gcconfig.h (HBLKSIZE): Define to 4096 on
+	powerpc64-linux.
+
 2005-05-09  Mike Stump  <mrs@apple.com>
 
 	* configure: Regenerate.
diff --git a/boehm-gc/include/private/gcconfig.h b/boehm-gc/include/private/gcconfig.h
index 5013dbd596b2..05b3832c176a 100644
--- a/boehm-gc/include/private/gcconfig.h
+++ b/boehm-gc/include/private/gcconfig.h
@@ -752,6 +752,7 @@
 #     if (defined (powerpc64) || defined(__powerpc64__))
 #       define ALIGNMENT 8
 #       define CPP_WORDSZ 64
+#       define HBLKSIZE 4096
 #     else
 #       define ALIGNMENT 4
 #     endif