diff --git a/xfhell-configure-c99.patch b/xfhell-configure-c99.patch
new file mode 100644
index 0000000..ed0ab56
--- /dev/null
+++ b/xfhell-configure-c99.patch
@@ -0,0 +1,16 @@
+Include <unistd.h> for the exit function.  This avoids an implicit
+function declaration and mishandling of this test with future
+compilers.
+
+diff --git a/m4/intdiv0.m4 b/m4/intdiv0.m4
+index 744b99ea8da87ca1..f5cbd3e944362697 100644
+--- a/m4/intdiv0.m4
++++ b/m4/intdiv0.m4
+@@ -33,6 +33,7 @@ changequote([,])dnl
+           [AC_LANG_SOURCE([[
+ #include <stdlib.h>
+ #include <signal.h>
++#include <unistd.h>
+ 
+ static void
+ sigfpe_handler (int sig)
diff --git a/xfhell.spec b/xfhell.spec
index a227e66..fcc2d00 100644
--- a/xfhell.spec
+++ b/xfhell.spec
@@ -1,9 +1,10 @@
 Name:           xfhell
 Version:        3.5.1
-Release:        1%{?dist}
+Release:        16%{?dist}
 Summary:        GTK based Ham Radio application for the Hellschreiber communications mode
 
-License:        GPLv2+
+# Automatically converted from old format: GPLv2+ - review is highly recommended.
+License:        GPL-2.0-or-later
 URL:            http://www.5b4az.org/
 Source0:        http://www.5b4az.org/pkg/%{name}/%{name}-%{version}.tar.bz2
 #add .desktop file
@@ -12,7 +13,9 @@ Source1:        %{name}.desktop
 Source2:        %{name}.png
 
 Patch0:         xfhell-Makefile.patch
+Patch1: xfhell-configure-c99.patch
 
+BuildRequires: make
 BuildRequires:  gcc gcc-c++
 BuildRequires:  autoconf, automake, libtool
 BuildRequires:  desktop-file-utils
@@ -64,6 +67,51 @@ cp -a doc/%{name}.1.gz %{buildroot}%{_mandir}/man1/
 
 
 %changelog
+* Fri Jul 17 2026 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-16
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild
+
+* Sat Jan 17 2026 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-15
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_44_Mass_Rebuild
+
+* Fri Jul 25 2025 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-14
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_43_Mass_Rebuild
+
+* Sun Jan 19 2025 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-13
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_42_Mass_Rebuild
+
+* Fri Jul 26 2024 Miroslav Suchý <msuchy@redhat.com> - 3.5.1-12
+- convert license to SPDX
+
+* Sat Jul 20 2024 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-11
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_41_Mass_Rebuild
+
+* Sat Jan 27 2024 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-10
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild
+
+* Sat Jul 22 2023 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-9
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild
+
+* Sat Jan 21 2023 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-8
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_38_Mass_Rebuild
+
+* Tue Jan 03 2023 Florian Weimer <fweimer@redhat.com> - 3.5.1-7
+- C99 compatibility fixes (#2157935)
+
+* Sat Jul 23 2022 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-6
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_37_Mass_Rebuild
+
+* Sat Jan 22 2022 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-5
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_36_Mass_Rebuild
+
+* Fri Jul 23 2021 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-4
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_35_Mass_Rebuild
+
+* Thu Jan 28 2021 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-3
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_34_Mass_Rebuild
+
+* Wed Jul 29 2020 Fedora Release Engineering <releng@fedoraproject.org> - 3.5.1-2
+- Rebuilt for https://fedoraproject.org/wiki/Fedora_33_Mass_Rebuild
+
 * Wed Feb 19 2020 Richard Shaw <hobbes1069@gmail.com> - 3.5.1-1
 - Update to 3.5.1.