diff --git a/boehm-gc/ChangeLog b/boehm-gc/ChangeLog
index cb097bcce68c..6f124526e3d3 100644
--- a/boehm-gc/ChangeLog
+++ b/boehm-gc/ChangeLog
@@ -1,3 +1,7 @@
+2013-12-21  Andreas Tobler  <andreast@gcc.gnu.org>
+
+	* include/private/gcconfig.h: Add FreeBSD powerpc64 defines.
+
 2013-09-20  Alan Modra  <amodra@gmail.com>
 
 	* configure: Regenerate.
diff --git a/boehm-gc/include/private/gcconfig.h b/boehm-gc/include/private/gcconfig.h
index 475bb2c191ad..7e081d993bb0 100644
--- a/boehm-gc/include/private/gcconfig.h
+++ b/boehm-gc/include/private/gcconfig.h
@@ -849,7 +849,15 @@
 #     define NO_PTHREAD_TRYLOCK
 #   endif
 #   ifdef FREEBSD
+#   if defined(__powerpc64__)
+#       define ALIGNMENT 8
+#       define CPP_WORDSZ 64
+#       ifndef HBLKSIZE
+#           define HBLKSIZE 4096
+#       endif
+#   else
 #       define ALIGNMENT 4
+#   endif
 #       define OS_TYPE "FREEBSD"
 #       ifndef GC_FREEBSD_THREADS
 #           define MPROTECT_VDB