diff --git a/ruby-3.3.12-Allow-up-to-1-send-from-exits-YJIT-stat-for-proc-tes.patch b/ruby-3.3.12-Allow-up-to-1-send-from-exits-YJIT-stat-for-proc-tes.patch
new file mode 100644
index 0000000..eed3485
--- /dev/null
+++ b/ruby-3.3.12-Allow-up-to-1-send-from-exits-YJIT-stat-for-proc-tes.patch
@@ -0,0 +1,32 @@
+From feee246753aa097e836a79ea8437f4b8c73df7e8 Mon Sep 17 00:00:00 2001
+From: Jarek Prokop <jprokop@redhat.com>
+Date: Tue, 21 Jul 2026 10:32:29 +0200
+Subject: [PATCH] Allow up to 1 send from exits YJIT stat for proc test.
+
+Add an allowed range of 0..1 for exits send stat.
+
+In some case, the stats contain extra stat under 'exits' for 'send'.
+
+In any other case, the stat is 0, and test passes.
+From RPM build of Ruby for Fedora distro family, the exits' stats emit 1 extra send.
+
+The commit that introduced fix and the offending test
+0cba8cf414dfd8ab30edc3081645405c165a81d5 for [Bug #21266]
+prevents a crash, which seems prevented here as well.
+---
+ test/ruby/test_yjit.rb | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/test/ruby/test_yjit.rb b/test/ruby/test_yjit.rb
+index 0d40d38872..df1b41aa16 100644
+--- a/test/ruby/test_yjit.rb
++++ b/test/ruby/test_yjit.rb
+@@ -1528,7 +1528,7 @@ def test_disable_stats
+ 
+   def test_proc_block_with_kwrest
+     # When the bug was present this required --yjit-stats to trigger.
+-    assert_compiles(<<~RUBY, result: {extra: 5})
++    assert_compiles(<<~RUBY, result: {extra: 5}, exits: {send: 0..1})
+       def foo = bar(w: 1, x: 2, y: 3, z: 4, extra: 5, &proc { _1 })
+       def bar(w:, x:, y:, z:, **kwrest) = yield kwrest
+ 
diff --git a/ruby.spec b/ruby.spec
index 7ab30e3..8e90cbe 100644
--- a/ruby.spec
+++ b/ruby.spec
@@ -293,6 +293,10 @@ Patch15: ruby-3.4.0-openssl-fix-test-provider-in-fips.patch
 # Fix the tests using SHA-1 Probabilistic Signature Scheme (PSS) parameters.
 # https://github.com/ruby/openssl/pull/879
 Patch16: ruby-3.4.2-openssl-Fix-SHA-1-PSS-tests.patch
+# Workaround for a weird failure that happens only during mockbuild of Ruby src.rpm
+# Cannot reproduce sufficiently so far for the issue to appear outside that environment.
+# See patch's commit message for more information.
+Patch17: ruby-3.3.12-Allow-up-to-1-send-from-exits-YJIT-stat-for-proc-tes.patch
 
 Requires: %{name}-libs%{?_isa} = %{version}-%{release}
 %{?with_rubypick:Suggests: rubypick}
@@ -776,6 +780,7 @@ analysis result in RBS format, a standard type description format for Ruby
 %patch 13 -p1
 %patch 15 -p1
 %patch 16 -p1
+%patch 17 -p1
 
 # Provide an example of usage of the tapset:
 cp -a %{SOURCE3} .