diff --git a/perl-5.31.0-perl-133989-scalar-the-argument-to-readline-if-any.patch b/perl-5.31.0-perl-133989-scalar-the-argument-to-readline-if-any.patch
new file mode 100644
index 0000000..902068b
--- /dev/null
+++ b/perl-5.31.0-perl-133989-scalar-the-argument-to-readline-if-any.patch
@@ -0,0 +1,47 @@
+From a8e0c1fd5ade7c30aa0782f1aea274ef89190f6d Mon Sep 17 00:00:00 2001
+From: Tony Cook <tony@develop-help.com>
+Date: Wed, 12 Jun 2019 15:21:47 +1000
+Subject: [PATCH] (perl #133989) scalar() the argument to readline, if any
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+C< readline @foo > would treat @foo as array.  If the array was empty
+this would push zero items and readline() would then pop one item,
+possibly underflowing the stack.
+
+Signed-off-by: Petr Písař <ppisar@redhat.com>
+---
+ op.c               | 1 +
+ t/lib/croak/pp_sys | 6 ++++++
+ 2 files changed, 7 insertions(+)
+
+diff --git a/op.c b/op.c
+index 6ad192307f..7aa002cadd 100644
+--- a/op.c
++++ b/op.c
+@@ -12142,6 +12142,7 @@ Perl_ck_readline(pTHX_ OP *o)
+     if (o->op_flags & OPf_KIDS) {
+ 	 OP *kid = cLISTOPo->op_first;
+ 	 if (kid->op_type == OP_RV2GV) kid->op_private |= OPpALLOW_FAKE;
++         scalar(kid);
+     }
+     else {
+ 	OP * const newop
+diff --git a/t/lib/croak/pp_sys b/t/lib/croak/pp_sys
+index be100da27a..cf9e4ef0ed 100644
+--- a/t/lib/croak/pp_sys
++++ b/t/lib/croak/pp_sys
+@@ -93,3 +93,9 @@ close $fh;
+ END { unlink $file; }
+ EXPECT
+ syswrite() isn't allowed on :utf8 handles at - line 5.
++########
++# NAME readline() didn't scalar() its argument
++# this would assert rather than failing on the method call
++E{0;readline@0}
++EXPECT
++Can't call method "E" without a package or object reference at - line 2.
+-- 
+2.20.1
+
diff --git a/perl.spec b/perl.spec
index 498caf9..0cd8d16 100644
--- a/perl.spec
+++ b/perl.spec
@@ -197,6 +197,10 @@ Patch30:        perl-5.31.0-perl-133936-ensure-TO-is-honoured-for-UDP-sock-send.
 Patch31:        perl-5.31.0-perl-133936-document-differences-between-IO-Socket-a.patch
 Patch32:        perl-5.31.0-perl-133936-make-send-a-bit-saner.patch
 
+# Fix a stack underflow in readline() if passed an empty array as an argument,
+# RT133989, fixed after 5.31.0
+Patch33:        perl-5.31.0-perl-133989-scalar-the-argument-to-readline-if-any.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
 
@@ -2747,6 +2751,7 @@ Perl extension for Version Objects
 %patch30 -p1
 %patch31 -p1
 %patch32 -p1
+%patch33 -p1
 %patch200 -p1
 %patch201 -p1
 
@@ -2786,6 +2791,7 @@ perl -x patchlevel.h \
     'Fedora Patch30: Fix changing packet destination sent from a UDP IO::Socket object (RT#133936)' \
     'Fedora Patch31: Fix changing packet destination sent from a UDP IO::Socket object (RT#133936)' \
     'Fedora Patch32: Fix changing packet destination sent from a UDP IO::Socket object (RT#133936)' \
+    'Fedora Patch33: Fix a stack underflow in readline() if passed an empty array as an argument (#RT133989)' \
     '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}
@@ -5046,6 +5052,8 @@ popd
 - Improve retrieving a scalar value of a variable modified in a signal handler
   (RT#134035)
 - Fix changing packet destination sent from a UDP IO::Socket object (RT#133936)
+- Fix a stack underflow in readline() if passed an empty array as an argument
+  (#RT133989)
 
 * Tue Jun 11 2019 Jitka Plesnikova <jplesnik@redhat.com> - 4:5.30.0-439
 - Define %%perl_vendor*, %%perl_archlib, %%perl_privlib, because in rpm