diff --git a/gambc-v4_6_5-reduce-opt.patch b/gambc-v4_6_5-reduce-opt.patch
new file mode 100644
index 0000000..756fe5d
--- /dev/null
+++ b/gambc-v4_6_5-reduce-opt.patch
@@ -0,0 +1,15 @@
+--- gambc-v4_6_5-devel/configure.reduce-opt	2012-03-15 00:32:35.000000000 +0700
++++ gambc-v4_6_5-devel/configure	2012-03-31 10:12:56.217457151 +0700
+@@ -22294,11 +22294,7 @@
+ { echo "$as_me:$LINENO: result: $DASH_fomit_frame_pointer" >&5
+ echo "${ECHO_T}$DASH_fomit_frame_pointer" >&6; }
+ 
+-  if test "$DASH_O2" != ""; then
+-    OPT_LEVEL_FLAG="$DASH_O2"
+-  else
+-    OPT_LEVEL_FLAG="$DASH_O1"
+-  fi
++  OPT_LEVEL_FLAG="$DASH_O1"
+ 
+ # It isn't clear these are useful:
+ #  AC_CHECK_C_COMPILER_OPT(-fexpensive-optimizations,DASH_fexpensive_optimizations)
diff --git a/gambit-c.spec b/gambit-c.spec
index 77fd6c0..5289a7f 100644
--- a/gambit-c.spec
+++ b/gambit-c.spec
@@ -23,6 +23,7 @@ URL:            http://www.iro.umontreal.ca/~gambit
 Source0:        http://www.iro.umontreal.ca/~gambit/download/gambit/v4.6/source/%{dirname}.tgz
 Source1:        gambit-init.el
 Patch0:         gambc-v4_2_8-modtime.patch
+Patch1:         gambc-v4_6_5-reduce-opt.patch
 
 BuildRequires:  emacs
 Requires:       gcc
@@ -83,6 +84,13 @@ Elisp source file for the Gambit-C editing mode for Emacs.
 %prep
 %setup -q -n %{dirname}
 %patch0 -p1 -b .modtime
+
+%ifarch ppc64
+%if ! %{with ppc64opt2}
+%patch1 -p1 -b .reduce-opt
+%endif
+%endif
+
 touch -r doc/gambit-c.info-2{,.tstamp}
 iconv -f iso88591 -t utf8 doc/gambit-c.info-2 -o doc/gambit-c.info-2.utf8
 touch -r doc/gambit-c.info-2{,.utf8}