diff --git a/fix-null-deref.patch b/fix-null-deref.patch
deleted file mode 100644
index 8ba59c9..0000000
--- a/fix-null-deref.patch
+++ /dev/null
@@ -1,23 +0,0 @@
-From f1b8e6323a8fdd029847b7efd400d5fc2ac9aecc Mon Sep 17 00:00:00 2001
-From: Eddie Kohler <ekohler@gmail.com>
-Date: Tue, 26 Sep 2017 08:46:13 -0700
-Subject: [PATCH] Don't release the uncompressed image if it's all there is.
-
-Fix #115, #116 issues reported by Zhao Liang, Huawei Weiran Labs.
----
- src/support.c | 2 +-
- 1 file changed, 1 insertion(+), 1 deletion(-)
-
-diff --git a/src/support.c b/src/support.c
-index e48075c..7978974 100644
---- a/src/support.c
-+++ b/src/support.c
-@@ -1405,7 +1405,7 @@ analyze_crop(int nmerger, Gt_Crop* crop, int compress_immediately)
-           }
- 
-         found_right:
--          if (compress_immediately > 0)
-+          if (compress_immediately > 0 && srci->compressed)
-             Gif_ReleaseUncompressedImage(srci);
-         }
- 
diff --git a/fix_double-free.patch b/fix_double-free.patch
deleted file mode 100644
index b99bf5e..0000000
--- a/fix_double-free.patch
+++ /dev/null
@@ -1,24 +0,0 @@
-From 118a46090c50829dc543179019e6140e1235f909 Mon Sep 17 00:00:00 2001
-From: Eddie Kohler <ekohler@gmail.com>
-Date: Sat, 2 Dec 2017 23:08:51 -0500
-Subject: [PATCH] gif_read: Set last_name = NULL unconditionally.
-
-With a non-malicious GIF, last_name is set to NULL when a name
-extension is followed by an image. Reported in #117, via
-Debian, via a KAIST fuzzing program.
----
- src/gifread.c | 1 +
- 1 file changed, 1 insertion(+)
-
-diff --git a/src/gifread.c b/src/gifread.c
-index eec4e31..9c287dd 100644
---- a/src/gifread.c
-+++ b/src/gifread.c
-@@ -900,6 +900,7 @@ read_gif(Gif_Reader *grr, int read_flags,
-   Gif_DeleteArray(gfc.suffix);
-   Gif_DeleteArray(gfc.length);
-   gfc.gfi = 0;
-+  last_name = 0;
- 
-   if (gfs)
-     gfs->errors = gfc.errors[1];
diff --git a/fix_gifdiff_null-deref.patch b/fix_gifdiff_null-deref.patch
deleted file mode 100644
index 8fdca1e..0000000
--- a/fix_gifdiff_null-deref.patch
+++ /dev/null
@@ -1,42 +0,0 @@
-From 263cd4519f45bc6ecde74ee280eb1d68ee2de642 Mon Sep 17 00:00:00 2001
-From: Eddie Kohler <ekohler@gmail.com>
-Date: Sat, 2 Dec 2017 23:10:30 -0500
-Subject: [PATCH] Two GIFs with zero images are the same.
-
-Another KAIST report; we null-dereferenced previously.
----
- src/gifdiff.c | 14 ++++++++------
- 1 file changed, 8 insertions(+), 6 deletions(-)
-
-diff --git a/src/gifdiff.c b/src/gifdiff.c
-index 04721d8..40da3c1 100644
---- a/src/gifdiff.c
-+++ b/src/gifdiff.c
-@@ -248,12 +248,6 @@ compare(Gif_Stream *s1, Gif_Stream *s2)
-   Gif_CalculateScreenSize(s1, 0);
-   Gif_CalculateScreenSize(s2, 0);
- 
--  if (s1->nimages != s2->nimages
--      && (s1->nimages == 0 || s2->nimages == 0)) {
--    different("frame counts differ: <#%d >#%d", s1->nimages, s2->nimages);
--    return DIFFERENT;
--  }
--
-   if (s1->screen_width != s2->screen_width
-       || s1->screen_height != s2->screen_height) {
-     different("screen sizes differ: <%dx%d >%dx%d", s1->screen_width,
-@@ -268,6 +262,14 @@ compare(Gif_Stream *s1, Gif_Stream *s2)
-     return DIFFERENT;
-   }
- 
-+  if (s1->nimages == 0 || s2->nimages == 0) {
-+    if (s1->nimages != s2->nimages) {
-+      different("frame counts differ: <#%d >#%d", s1->nimages, s2->nimages);
-+      return DIFFERENT;
-+    } else
-+      return SAME;
-+  }
-+
-   /* Create arrays for the image data */
-   screen_width = s1->screen_width;
-   screen_height = s1->screen_height;
diff --git a/gifsicle-1.90.tar.gz b/gifsicle-1.90.tar.gz
deleted file mode 100644
index e4b25be..0000000
--- a/gifsicle-1.90.tar.gz
+++ /dev/null
@@ -1,3 +0,0 @@
-version https://git-lfs.github.com/spec/v1
-oid sha256:2d73b096752d58fa604cea559199aa6f55b45a3ec833898f94ff7997d22b834d
-size 571910
diff --git a/gifsicle-1.91.tar.gz b/gifsicle-1.91.tar.gz
new file mode 100644
index 0000000..59886e5
--- /dev/null
+++ b/gifsicle-1.91.tar.gz
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:0a4ee602aa244cdcdd86a250a6b39c94d8343cf526b8fae862d8a0efc337a800
+size 571588
diff --git a/gifsicle.changes b/gifsicle.changes
index bc48039..1e65ae9 100644
--- a/gifsicle.changes
+++ b/gifsicle.changes
@@ -1,3 +1,11 @@
+-------------------------------------------------------------------
+Fri Jan  5 23:01:51 UTC 2018 - manfred99@gmx.ch
+
+- drop patches fix_double-free.patch, fix_gifdiff_null-deref.patch
+    and fix-null-deref.patch
+- upgrade to version 1.91:
+  * Several security bug fixes with malicious GIFs.
+
 -------------------------------------------------------------------
 Wed Jan  3 20:58:34 UTC 2018 - manfred99@gmx.ch
 
diff --git a/gifsicle.spec b/gifsicle.spec
index 034d263..f8a7476 100644
--- a/gifsicle.spec
+++ b/gifsicle.spec
@@ -17,19 +17,13 @@
 
 
 Name:           gifsicle
-Version:        1.90
+Version:        1.91
 Release:        0
 Summary:        Creating and editing GIF images and animations
 License:        GPL-2.0
 Group:          Productivity/Graphics/Other
 Url:            https://www.lcdf.org/gifsicle/
 Source:         https://www.lcdf.org/gifsicle/%{name}-%{version}.tar.gz
-# PATCH-FIX-UPSTREAM fix-null-deref.patch
-Patch0:         fix-null-deref.patch
-# PATCH-FIX-UPSTREAM fix_double-free.patch
-Patch1:         fix_double-free.patch
-# PATCH-FIX-UPSTREAM fix_gifdiff_null-deref.patch
-Patch2:         fix_gifdiff_null-deref.patch
 Obsoletes:      ungifsicle < %{version}
 Provides:       ungifsicle = %{version}
 BuildRequires:  pkgconfig(x11)
@@ -56,9 +50,6 @@ appearance.
 
 %prep
 %setup -q
-%patch0 -p1
-%patch1 -p1
-%patch2 -p1
 
 %build
 %configure