diff --git a/fix-compiler-errors.patch b/fix-compiler-errors.patch
new file mode 100644
index 0000000..70088fe
--- /dev/null
+++ b/fix-compiler-errors.patch
@@ -0,0 +1,110 @@
+From 5522116cd03a14e72caee50e64902df7b5543028 Mon Sep 17 00:00:00 2001
+From: Seth Morton <seth.m.morton@gmail.com>
+Date: Mon, 21 Oct 2024 21:55:42 -0700
+Subject: [PATCH] Update CI configuration
+
+---
+ dev/formatting.py                        |    2 +-
+ include/fastnumbers/third_party/ipow.hpp |    6 ++++--
+ setup.py                                 |    8 ++++++++
+ src/cpp/parser.cpp                       |    3 +++
+ tox.ini                                  |   13 +++++++++++--
+ 5 files changed, 27 insertions(+), 5 deletions(-)
+
+--- a/dev/formatting.py
++++ b/dev/formatting.py
+@@ -52,6 +52,6 @@ any_cpp_formatting = any(
+ # "Roll up" what happened into a single exit code.
+ all_return_zero = all(ret.returncode == 0 for ret in [black_ret, clang_format_ret])
+ if any_cpp_formatting or not all_return_zero:
+-    sys.exit("Not all files are formatted correctly. Run 'tox -e format'.")
++    sys.exit("Not all files are formatted correctly. Run 'tox run -e format'.")
+ else:
+     sys.exit(0)
+--- a/include/fastnumbers/third_party/ipow.hpp
++++ b/include/fastnumbers/third_party/ipow.hpp
+@@ -58,8 +58,10 @@ inline T1 ipow(T1 base, T2 exp) {
+             return 1;
+         }
+         
+-        if (base == -1) {
+-            return 1 - 2 * (exp & 1);
++        if constexpr(std::is_signed_v<T1>) {
++            if (base == -1) {
++                return 1 - 2 * (exp & 1);
++            }
+         }
+         
+         return 0;
+--- a/setup.py
++++ b/setup.py
+@@ -9,6 +9,7 @@ from setuptools import Extension, find_p
+ 
+ 
+ # Compilation arguments are platform-dependent
++link_args = ["-lm"]
+ if sys.platform == "win32":
+     compile_args = [
+         "/std:c++17",
+@@ -19,6 +20,8 @@ if sys.platform == "win32":
+     if "FN_DEBUG" in os.environ or "FN_COV" in os.environ:
+         compile_args.append("/Od")
+         compile_args.append("/Z7")
++    if "FN_WARNINGS_AS_ERRORS" in os.environ:
++         compile_args.append("/WX")
+ else:
+     compile_args = [
+         "-std=c++17",
+@@ -31,6 +34,11 @@ else:
+     if "FN_DEBUG" in os.environ or "FN_COV" in os.environ:
+         compile_args.append("-Og")
+         compile_args.append("-g")
++        if "FN_COV" in os.environ:
++            compile_args.append("--coverage")
++            link_args.append("--coverage")
++    if "FN_WARNINGS_AS_ERRORS" in os.environ:
++        compile_args.append("-Werror")
+ 
+ 
+ ext = [
+--- a/src/cpp/parser.cpp
++++ b/src/cpp/parser.cpp
+@@ -460,4 +460,7 @@ NumberFlags CharacterParser::get_number_
+     case StringType::INTLIKE_FLOAT:
+         return flag_wrap(NumberType::Float | NumberType::IntLike);
+     }
++
++    /* Is not reachable, but silences compiler warnings. */
++    return NumberType::INVALID;
+ }
+--- a/tox.ini
++++ b/tox.ini
+@@ -4,10 +4,11 @@
+ # and then run "tox" from this directory.
+ 
+ [tox]
+-envlist = py37, py38, py39, py310, py311, py12
++envlist = lint, mypy, py37, py38, py39, py310, py311, py12
+ # Other valid environments are:
+ #   format
+-#   format-check
++#   lint
++#   mypy
+ #   docs
+ #   bump
+ #   clean
+@@ -50,6 +51,14 @@ deps =
+     clang-format
+ commands = {envpython} dev/formatting.py
+ 
++# Check code quality.
++[testenv:lint]
++setenv =
++    FN_WARNINGS_AS_ERRORS=1
++deps =
++    ruff
++    clang-format
++
+ # Type checking
+ [testenv:mypy]
+ deps =
diff --git a/python-fastnumbers.changes b/python-fastnumbers.changes
index 898159c..14b39b4 100644
--- a/python-fastnumbers.changes
+++ b/python-fastnumbers.changes
@@ -1,3 +1,10 @@
+-------------------------------------------------------------------
+Fri Nov 22 18:57:14 UTC 2024 - Matej Cepl <mcepl@cepl.eu>
+
+- Add fix-compiler-errors.patch with upstream fixes for compiler
+  errors.
+- Use %pytest_arch instead of home made calling of pytest.
+
 -------------------------------------------------------------------
 Fri Dec 29 18:35:47 UTC 2023 - Dirk Müller <dmueller@suse.com>
 
diff --git a/python-fastnumbers.spec b/python-fastnumbers.spec
index cf7e2e9..f2df9a3 100644
--- a/python-fastnumbers.spec
+++ b/python-fastnumbers.spec
@@ -1,7 +1,7 @@
 #
 # spec file for package python-fastnumbers
 #
-# Copyright (c) 2023 SUSE LLC
+# Copyright (c) 2024 SUSE LLC
 #
 # All modifications and additions to the file contributed by third parties
 # remain the property of their copyright owners, unless otherwise agreed
@@ -24,6 +24,9 @@ Summary:        Drop-in replacement for Python's int and float
 License:        MIT
 URL:            https://github.com/SethMMorton/fastnumbers
 Source:         https://files.pythonhosted.org/packages/source/f/fastnumbers/fastnumbers-%{version}.tar.gz
+# PATCH-FIX-UPSTREAM fix-compiler-errors.patch mcepl@suse.com
+# Code from gh#SethMMorton/fastnumbers@5522116cd03a and gh#SethMMorton/fastnumbers@8d2104e5cd93
+Patch0:         fix-compiler-errors.patch
 BuildRequires:  %{python_module devel}
 BuildRequires:  %{python_module pip}
 BuildRequires:  %{python_module typing-extensions}
@@ -58,7 +61,7 @@ fastnumbers is a Python module with three objectives:
    an input could be converted to int or float.
 
 %prep
-%setup -q -n fastnumbers-%{version}
+%autosetup -p1 -n fastnumbers-%{version}
 
 %build
 %if 0%{?suse_version} <= 1500
@@ -73,9 +76,7 @@ export CFLAGS="%{optflags} -Wno-error=return-type"
 %python_expand %fdupes %{buildroot}%{$python_sitearch}
 
 %check
-%{python_expand export PYTHONPATH=%{buildroot}%{$python_sitearch}
-pytest-%{$python_bin_suffix}
-}
+%pytest_arch
 
 %files %{python_files}
 %doc README.rst