diff --git a/perl-5.28.1-PATCH-perl-133880-assertion-failure.patch b/perl-5.28.1-PATCH-perl-133880-assertion-failure.patch
new file mode 100644
index 0000000..b8a0b46
--- /dev/null
+++ b/perl-5.28.1-PATCH-perl-133880-assertion-failure.patch
@@ -0,0 +1,69 @@
+From d434dd3ec16dc1202626e9868f177203e2a86da5 Mon Sep 17 00:00:00 2001
+From: Karl Williamson <khw@cpan.org>
+Date: Thu, 21 Mar 2019 09:35:49 -0600
+Subject: [PATCH] PATCH: [perl #133880] assertion failure
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+This was caused by attempting to continue parsing after an error is
+found, and later assuming that what came before was valid.  The fix is
+to put in something valid that's usable until the parse eventually dies
+from what caused this, or some other error.
+
+Signed-off-by: Ported to 5.28.1 from
+ef65a74af186beb93566cf827c5f543f4aa14645.
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ t/op/tr.t | 8 +++++++-
+ toke.c    | 8 ++++++--
+ 2 files changed, 13 insertions(+), 3 deletions(-)
+
+diff --git a/t/op/tr.t b/t/op/tr.t
+index 0f74936..47d603d 100644
+--- a/t/op/tr.t
++++ b/t/op/tr.t
+@@ -13,7 +13,7 @@ BEGIN {
+ 
+ use utf8;
+ 
+-plan tests => 300;
++plan tests => 301;
+ 
+ # Test this first before we extend the stack with other operations.
+ # This caused an asan failure due to a bad write past the end of the stack.
+@@ -1137,6 +1137,12 @@ for ("", nullrocow) {
+     [\x{E5CD}-\x{E5DF}\x{EA80}-\x{EAFA}\x{EB0E}-\x{EB8E}\x{EAFB}-\x{EB0D}\x{E5B5}-\x{E5CC}];
+ 
+     is $x, "\x{E5CE}", '[perl #130656]';
++
++}
++
++{
++    fresh_perl_like('y/\x{a00}0-\N{}//', qr/Unknown charname/, { },
++                    'RT #133880 illegal \N{}');
+ }
+ 
+ 1;
+diff --git a/toke.c b/toke.c
+index 3164df5..4747ef5 100644
+--- a/toke.c
++++ b/toke.c
+@@ -3770,8 +3770,12 @@ S_scan_const(pTHX_ char *start)
+ 		    }
+ 		}
+ 		else /* Here is \N{NAME} but not \N{U+...}. */
+-                     if ((res = get_and_check_backslash_N_name(s, e)))
+-                {
++                     if (! (res = get_and_check_backslash_N_name(s, e)))
++                {   /* Failed.  We should die eventually, but for now use a NUL
++                       to keep parsing */
++                    *d++ = '\0';
++                }
++                else {  /* Successfully evaluated the name */
+                     STRLEN len;
+                     const char *str = SvPV_const(res, len);
+                     if (PL_lex_inpat) {
+-- 
+2.20.1
+
diff --git a/perl.spec b/perl.spec
index 0080681..b72e84f 100644
--- a/perl.spec
+++ b/perl.spec
@@ -268,6 +268,10 @@ Patch57:        perl-5.29.8-fix-blead-on-non-threaded-builds.patch
 # in upstream after 5.29.8
 Patch58:        perl-5.29.8-handle-scope-error-in-qr.patch
 
+# Fix a buffer overread when parsing a regular expression with an unknown
+# character name, RT#133880, in upstream after 5.29.9
+Patch59:        perl-5.28.1-PATCH-perl-133880-assertion-failure.patch
+
 # Link XS modules to libperl.so with EU::CBuilder on Linux, bug #960048
 Patch200:       perl-5.16.3-Link-XS-modules-to-libperl.so-with-EU-CBuilder-on-Li.patch
 
@@ -2882,6 +2886,7 @@ Perl extension for Version Objects
 %patch56 -p1
 %patch57 -p1
 %patch58 -p1
+%patch59 -p1
 %patch200 -p1
 %patch201 -p1
 
@@ -2932,6 +2937,7 @@ perl -x patchlevel.h \
     'Fedora Patch55: Fix extending a stack in Perl parser (RT#133778)' \
     'Fedora Patch56: Fix a leak when compiling a typed hash dereference' \
     'Fedora Patch58: Fix a buffer overread when handling a scope error in qr/\(?{/ (RT#133879)' \
+    'Fedora Patch59: Fix a buffer overread when parsing a regular expression with an unknown character name (RT#133880)' \
     'Fedora Patch200: Link XS modules to libperl.so with EU::CBuilder on Linux' \
     'Fedora Patch201: Link XS modules to libperl.so with EU::MM on Linux' \
     %{nil}
@@ -5223,6 +5229,8 @@ popd
 * Fri Apr 05 2019 Petr Pisar <ppisar@redhat.com> - 4:5.28.1-435
 - Fix a leak when compiling a typed hash dereference
 - Fix a buffer overread when handling a scope error in qr/\(?{/ (RT#133879)
+- Fix a buffer overread when parsing a regular expression with an unknown
+  character name (RT#133880)
 
 * Tue Mar 05 2019 Björn Esser <besser82@fedoraproject.org> - 4:5.28.1-434
 - Add explicit Requires: libxcrypt-devel to devel sub-package (bug #1666098)