diff --git a/ruby-2.5.0-Revert-runruby-test-with-smallest-possible-machine-stack.patch b/ruby-2.5.0-Revert-runruby-test-with-smallest-possible-machine-stack.patch
new file mode 100644
index 0000000..96da001
--- /dev/null
+++ b/ruby-2.5.0-Revert-runruby-test-with-smallest-possible-machine-stack.patch
@@ -0,0 +1,32 @@
+From 68b8e9b42f1baf67f8ef9535d213fd0bd7ae42f4 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?V=C3=ADt=20Ondruch?= <vondruch@redhat.com>
+Date: Fri, 25 Aug 2017 13:21:56 +0200
+Subject: [PATCH] Revert "tool/runruby.rb: test with smallest possible machine
+ stack"
+
+This reverts commit c4e2cf466448f4283fd3f8a17a73f5fa9b745fe1.
+---
+ tool/runruby.rb | 7 +------
+ 1 file changed, 1 insertion(+), 6 deletions(-)
+
+diff --git a/tool/runruby.rb b/tool/runruby.rb
+index f6c46779e3..cade314748 100755
+--- a/tool/runruby.rb
++++ b/tool/runruby.rb
+@@ -67,12 +67,7 @@ def File.realpath(*args)
+ libs << File.expand_path("lib", srcdir)
+ config["bindir"] = abs_archdir
+ 
+-env = {
+-  # Test with the smallest possible machine stack sizes.
+-  # These values are clamped to machine-dependent minimum values in vm_core.h
+-  'RUBY_THREAD_MACHINE_STACK_SIZE' => '1',
+-  'RUBY_FIBER_MACHINE_STACK_SIZE' => '1',
+-}
++env = {}
+ 
+ runner = File.join(abs_archdir, "ruby-runner#{config['EXEEXT']}")
+ runner = nil unless File.exist?(runner)
+-- 
+2.14.1
+
diff --git a/ruby.spec b/ruby.spec
index 6b17bb5..b29941d 100644
--- a/ruby.spec
+++ b/ruby.spec
@@ -10,7 +10,7 @@
 #%%global milestone rc1
 
 # Keep the revision enabled for pre-releases from SVN.
-%global revision 59643
+%global revision 59657
 
 %global ruby_archive %{name}-%{ruby_version}
 
@@ -129,6 +129,10 @@ Patch7: ruby-2.2.3-Generate-preludes-using-miniruby.patch
 # https://bugs.ruby-lang.org/issues/12666
 Patch9: ruby-2.3.1-Rely-on-ldd-to-detect-glibc.patch
 
+# Avoids SEGV in TestBacktrace#test_caller_lev segaults on PPC.
+# https://bugs.ruby-lang.org/issues/13757
+Patch100: ruby-2.5.0-Revert-runruby-test-with-smallest-possible-machine-stack.patch
+
 Requires: %{name}-libs%{?_isa} = %{version}-%{release}
 Suggests: rubypick
 Recommends: ruby(rubygems) >= %{rubygems_version}
@@ -508,6 +512,8 @@ rm -rf ext/fiddle/libffi*
 %patch7 -p1
 %patch9 -p1
 
+%patch100 -p1
+
 # Provide an example of usage of the tapset:
 cp -a %{SOURCE3} .
 
@@ -1045,8 +1051,8 @@ make check TESTS="-v $DISABLE_TESTS"
 %{gem_dir}/specifications/xmlrpc-%{xmlrpc_version}.gemspec
 
 %changelog
-* Tue Apr 11 2017 Vít Ondruch <vondruch@redhat.com> - 2.5.0-0.1.r59643
-- Upgrade to Ruby 2.5.0 (r59643).
+* Tue Apr 11 2017 Vít Ondruch <vondruch@redhat.com> - 2.5.0-0.1.r59657
+- Upgrade to Ruby 2.5.0 (r59657).
 
 * Mon Apr 03 2017 Vít Ondruch <vondruch@redhat.com> - 2.4.1-79
 - Update to Ruby 2.4.1.