diff --git a/perl-5.33.0-XSUB.h-fix-MARK-and-items-variables-inside-BOOT-XSUB.patch b/perl-5.33.0-XSUB.h-fix-MARK-and-items-variables-inside-BOOT-XSUB.patch
new file mode 100644
index 0000000..fe4d653
--- /dev/null
+++ b/perl-5.33.0-XSUB.h-fix-MARK-and-items-variables-inside-BOOT-XSUB.patch
@@ -0,0 +1,45 @@
+From 313464947382fab07299af0061f419a55540356a Mon Sep 17 00:00:00 2001
+From: Tomasz Konojacki <me@xenu.pl>
+Date: Mon, 27 Apr 2020 08:31:47 +0200
+Subject: [PATCH] XSUB.h: fix MARK and items variables inside BOOT XSUBs
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+ax was incremented by Perl_xs_handshake() and because of that
+MARK and items were off by one inside BOOT XSUBs.
+
+fixes #17755
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ XSUB.h | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/XSUB.h b/XSUB.h
+index e3147ce9fb..5f17a5acde 100644
+--- a/XSUB.h
++++ b/XSUB.h
+@@ -160,16 +160,16 @@ is a lexical C<$_> in scope.
+    PL_xsubfilename. */
+ #define dXSBOOTARGSXSAPIVERCHK  \
+ 	I32 ax = XS_BOTHVERSION_SETXSUBFN_POPMARK_BOOTCHECK;	\
+-	SV **mark = PL_stack_base + ax; dSP; dITEMS
++	SV **mark = PL_stack_base + ax - 1; dSP; dITEMS
+ #define dXSBOOTARGSAPIVERCHK  \
+ 	I32 ax = XS_APIVERSION_SETXSUBFN_POPMARK_BOOTCHECK;	\
+-	SV **mark = PL_stack_base + ax; dSP; dITEMS
++	SV **mark = PL_stack_base + ax - 1; dSP; dITEMS
+ /* dXSBOOTARGSNOVERCHK has no API in xsubpp to choose it so do
+ #undef dXSBOOTARGSXSAPIVERCHK
+ #define dXSBOOTARGSXSAPIVERCHK dXSBOOTARGSNOVERCHK */
+ #define dXSBOOTARGSNOVERCHK  \
+ 	I32 ax = XS_SETXSUBFN_POPMARK;  \
+-	SV **mark = PL_stack_base + ax; dSP; dITEMS
++	SV **mark = PL_stack_base + ax - 1; dSP; dITEMS
+ 
+ #define dXSTARG SV * const targ = ((PL_op->op_private & OPpENTERSUB_HASTARG) \
+ 			     ? PAD_SV(PL_op->op_targ) : sv_newmortal())
+-- 
+2.25.4
+
diff --git a/perl.spec b/perl.spec
index d332b84..d949f4d 100644
--- a/perl.spec
+++ b/perl.spec
@@ -205,6 +205,10 @@ Patch26:        perl-5.33.0-reentr.c-Prevent-infinite-looping.patch
 # in upstream after 5.33.0
 Patch27:        perl-5.33.0-perl-17844-don-t-update-SvCUR-until-after-we-ve-done.patch
 
+# Fix a number of arguments passed to a BOOT XS subroutine, GH#17755,
+# in upstream after 5.33.0
+Patch28:        perl-5.33.0-XSUB.h-fix-MARK-and-items-variables-inside-BOOT-XSUB.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
 
@@ -4218,6 +4222,7 @@ you're not running VMS, this module does nothing.
 %patch25 -p1
 %patch26 -p1
 %patch27 -p1
+%patch28 -p1
 %patch200 -p1
 %patch201 -p1
 
@@ -4252,6 +4257,7 @@ perl -x patchlevel.h \
     'Fedora Patch25: Fix a buffer size for asctime_r() and ctime_r() functions' \
     'Fedora Patch26: Prevent from an integer overflow in RenewDouble() macro' \
     'Fedora Patch27: Fix a buffer overread in when reallocating formats (GH#17844)' \
+    'Fedora Patch28: Fix a number of arguments passed to a BOOT XS subroutine (GH#17755)' \
     '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}
@@ -6981,6 +6987,7 @@ popd
 - Fix a buffer size for asctime_r() and ctime_r() functions
 - Prevent from an integer overflow in RenewDouble() macro
 - Fix a buffer overread in when reallocating formats (GH#17844)
+- Fix a number of arguments passed to a BOOT XS subroutine (GH#17755)
 
 * Tue Jul 28 2020 Fedora Release Engineering <releng@fedoraproject.org> - 4:5.32.0-458
 - Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild