diff --git a/0001-Revert-Ignore-the-always-part-of-inline-always-in-MI.patch b/0001-Revert-Ignore-the-always-part-of-inline-always-in-MI.patch
new file mode 100644
index 0000000..cefda23
--- /dev/null
+++ b/0001-Revert-Ignore-the-always-part-of-inline-always-in-MI.patch
@@ -0,0 +1,41 @@
+From 816745286555b978e8b0fe05d3bc99d28218587b Mon Sep 17 00:00:00 2001
+From: Josh Stone <jistone@redhat.com>
+Date: Thu, 31 Aug 2023 13:37:23 -0700
+Subject: [PATCH] Revert "Ignore the always part of #[inline(always)] in MIR
+ inlining"
+
+This reverts part of commit c153f3a356b0e7917c91d3a804b93fadffb778b0.
+
+On Fedora 37 with LLVM 15, we were seeing strange errors from the stage2
+rustc on ppc64le, which seemed to imply bad codegen in rustc itself. Git
+bisect pointed to this MIR inlining change -- it's not likely the root
+cause, since later Fedora with LLVM 16 is working, but this will unblock
+us for now.
+---
+ compiler/rustc_mir_transform/src/inline.rs | 9 ++++-----
+ 1 file changed, 4 insertions(+), 5 deletions(-)
+
+diff --git a/compiler/rustc_mir_transform/src/inline.rs b/compiler/rustc_mir_transform/src/inline.rs
+index fc9e18378d5a..800155922b28 100644
+--- a/compiler/rustc_mir_transform/src/inline.rs
++++ b/compiler/rustc_mir_transform/src/inline.rs
+@@ -499,12 +499,11 @@ fn check_mir_body(
+             }
+         }
+ 
+-        // N.B. We still apply our cost threshold to #[inline(always)] functions.
+-        // That attribute is often applied to very large functions that exceed LLVM's (very
+-        // generous) inlining threshold. Such functions are very poor MIR inlining candidates.
+-        // Always inlining #[inline(always)] functions in MIR, on net, slows down the compiler.
+         let cost = checker.cost;
+-        if cost <= threshold {
++        if let InlineAttr::Always = callee_attrs.inline {
++            debug!("INLINING {:?} because inline(always) [cost={}]", callsite, cost);
++            Ok(())
++        } else if cost <= threshold {
+             debug!("INLINING {:?} [cost={} <= threshold={}]", callsite, cost, threshold);
+             Ok(())
+         } else {
+-- 
+2.41.0
+
diff --git a/rust.spec b/rust.spec
index 6b51a37..c2b3c03 100644
--- a/rust.spec
+++ b/rust.spec
@@ -118,6 +118,9 @@ Patch3:         0001-Let-environment-variables-override-some-default-CPUs.patch
 Patch4:         0001-bootstrap-allow-disabling-target-self-contained.patch
 Patch5:         0002-set-an-external-library-path-for-wasm32-wasi.patch
 
+# Revert a MIR inlining change that broke ppc64le with LLVM 15.
+Patch6:         0001-Revert-Ignore-the-always-part-of-inline-always-in-MI.patch
+
 ### RHEL-specific patches below ###
 
 # Simple rpm macros for rust-toolset (as opposed to full rust-packaging)
@@ -558,6 +561,7 @@ rm -rf %{wasi_libc_dir}/dlmalloc/
 %if %without bundled_wasi_libc
 %patch -P5 -p1
 %endif
+%patch -P6 -p1
 
 %if %with disabled_libssh2
 %patch -P100 -p1