diff --git a/ghostscript-gdevcups-debug-uninit.patch b/ghostscript-gdevcups-debug-uninit.patch
new file mode 100644
index 0000000..967050b
--- /dev/null
+++ b/ghostscript-gdevcups-debug-uninit.patch
@@ -0,0 +1,17 @@
+diff -up ghostscript-9.00/cups/gdevcups.c.gdevcups-debug-uninit ghostscript-9.00/cups/gdevcups.c
+--- ghostscript-9.00/cups/gdevcups.c.gdevcups-debug-uninit	2010-08-12 19:10:47.000000000 +0100
++++ ghostscript-9.00/cups/gdevcups.c	2010-10-14 17:39:39.834994296 +0100
+@@ -807,9 +807,10 @@ cups_get_matrix(gx_device *pdev,	/* I - 
+   dprintf4("DEBUG2: PageSize = [ %d %d ], HWResolution = [ %d %d ]\n",
+ 	   cups->header.PageSize[0], cups->header.PageSize[1],
+ 	   cups->header.HWResolution[0], cups->header.HWResolution[1]);
+-  dprintf4("DEBUG2: HWMargins = [ %.3f %.3f %.3f %.3f ]\n",
+-	   pdev->HWMargins[0], pdev->HWMargins[1], pdev->HWMargins[2],
+-	   pdev->HWMargins[3]);
++  if (size_set)
++    dprintf4("DEBUG2: HWMargins = [ %.3f %.3f %.3f %.3f ]\n",
++	     pdev->HWMargins[0], pdev->HWMargins[1], pdev->HWMargins[2],
++	     pdev->HWMargins[3]);
+   dprintf6("DEBUG2: matrix = [ %.3f %.3f %.3f %.3f %.3f %.3f ]\n",
+ 	   pmat->xx, pmat->xy, pmat->yx, pmat->yy, pmat->tx, pmat->ty);
+ #endif /* DEBUG */
diff --git a/ghostscript.spec b/ghostscript.spec
index 7974be1..c3a9a02 100644
--- a/ghostscript.spec
+++ b/ghostscript.spec
@@ -5,7 +5,7 @@ Summary: A PostScript interpreter and renderer
 Name: ghostscript
 Version: %{gs_ver}
 
-Release: 4%{?dist}
+Release: 5%{?dist}
 
 # Included CMap data is Redistributable, no modification permitted,
 # see http://bugzilla.redhat.com/487510
@@ -28,6 +28,7 @@ Patch12: ghostscript-vsnprintf.patch
 Patch21: ghostscript-jbig2-image-refcount.patch
 Patch27: ghostscript-Fontmap.local.patch
 Patch28: ghostscript-iccprofiles-initdir.patch
+Patch29: ghostscript-gdevcups-debug-uninit.patch
 
 Requires: urw-fonts >= 1.1, ghostscript-fonts
 BuildRequires: xz
@@ -141,6 +142,9 @@ rm -rf libpng zlib jpeg jasper
 # Don't assume %rom% device is available for initial ICC profile dir.
 %patch28 -p1 -b .iccprofiles-initdir
 
+# gdevcups: don't use uninitialized variables in debugging output.
+%patch29 -p1 -b .gdevcups-debug-uninit
+
 # Convert manual pages to UTF-8
 from8859_1() {
         iconv -f iso-8859-1 -t utf-8 < "$1" > "${1}_"
@@ -323,6 +327,10 @@ rm -rf $RPM_BUILD_ROOT
 %{_libdir}/libgs.so
 
 %changelog
+* Thu Oct 14 2010 Tim Waugh <twaugh@redhat.com> 9.00-5
+- gdevcups: don't use uninitialized variables in debugging output
+  (Ghostscript bug #691683).
+
 * Fri Oct  1 2010 Tim Waugh <twaugh@redhat.com> 9.00-4
 - Reverted incorrect change introduced to fix bug #635786.