diff --git a/boost-1.76.0-fix-narrowing-conversions-for-ppc.patch b/boost-1.76.0-fix-narrowing-conversions-for-ppc.patch
new file mode 100644
index 0000000..42662dd
--- /dev/null
+++ b/boost-1.76.0-fix-narrowing-conversions-for-ppc.patch
@@ -0,0 +1,32 @@
+From 0039878782516ea3313608f99f0d50e846151bc2 Mon Sep 17 00:00:00 2001
+From: Jonathan Wakely <jwakely@fedoraproject.org>
+Date: Mon, 31 Jan 2022 11:37:29 +0000
+Subject: [PATCH] Fix narrowing conversions for ppc
+
+These constants are too large for `long long` so are unsigned,
+and then cannot be narrowed to the signed type.
+
+Fixes #29
+---
+ .../numeric/interval/detail/ppc_rounding_control.hpp      | 8 ++++----
+ 1 file changed, 4 insertions(+), 4 deletions(-)
+
+diff --git a/include/boost/numeric/interval/detail/ppc_rounding_control.hpp b/include/boost/numeric/interval/detail/ppc_rounding_control.hpp
+index 87fe8ee..99f9986 100644
+--- a/include/boost/numeric/interval/detail/ppc_rounding_control.hpp
++++ b/include/boost/numeric/interval/detail/ppc_rounding_control.hpp
+@@ -28,10 +28,10 @@ typedef union {
+   double dmode;
+ } rounding_mode_struct;
+ 
+-static const rounding_mode_struct mode_upward      = { 0xFFF8000000000002LL };
+-static const rounding_mode_struct mode_downward    = { 0xFFF8000000000003LL };
+-static const rounding_mode_struct mode_to_nearest  = { 0xFFF8000000000000LL };
+-static const rounding_mode_struct mode_toward_zero = { 0xFFF8000000000001LL };
++static const rounding_mode_struct mode_upward      = { (::boost::long_long_type)0xFFF8000000000002LL };
++static const rounding_mode_struct mode_downward    = { (::boost::long_long_type)0xFFF8000000000003LL };
++static const rounding_mode_struct mode_to_nearest  = { (::boost::long_long_type)0xFFF8000000000000LL };
++static const rounding_mode_struct mode_toward_zero = { (::boost::long_long_type)0xFFF8000000000001LL };
+ 
+ struct ppc_rounding_control
+ {
diff --git a/boost.spec b/boost.spec
index 400890e..18744b5 100644
--- a/boost.spec
+++ b/boost.spec
@@ -42,7 +42,7 @@ Name: boost
 %global real_name boost
 Summary: The free peer-reviewed portable C++ source libraries
 Version: 1.76.0
-Release: 8%{?dist}
+Release: 9%{?dist}
 License: Boost and MIT and Python
 
 # Replace each . with _ in %%{version}
@@ -165,6 +165,11 @@ Patch102: boost-1.76.0-random-test.patch
 # fixes ppc64le issue https://github.com/boostorg/multiprecision/issues/419
 Patch103: boost-1.76.0-fix_multiprecision_issue_419-ppc64le.patch
 
+# PR https://github.com/boostorg/interval/pull/30
+# Fixes narrowing conversions for ppc -
+#   https://github.com/boostorg/interval/issues/29
+Patch104: boost-1.76.0-fix-narrowing-conversions-for-ppc.patch 
+
 %bcond_with tests
 %bcond_with docs_generated
 
@@ -690,6 +695,7 @@ find ./boost -name '*.hpp' -perm /111 | xargs chmod a-x
 %patch101 -p1
 %patch102 -p1
 %patch103 -p2
+%patch104 -p2
 
 %build
 %set_build_flags
@@ -1291,6 +1297,10 @@ fi
 %{_mandir}/man1/b2.1*
 
 %changelog
+* Wed Feb  2 2022 Thomas Rodgers <trodgers@redhat.com> - 1.76.0-9
+- Add patch to fix narrowing conversions on ppc64le
+  https://github.com/boostorg/interval/issues/29
+
 * Tue Feb  1 2022 Laurent Rineau <laurent.rineau@cgal.org> - 1.76.0-8
 - Add patch to fix Boost Multiprecision on ppc64le
   https://github.com/boostorg/multiprecision/issues/419