diff --git a/telegram-desktop.changes b/telegram-desktop.changes
index 477eb65..18fa800 100644
--- a/telegram-desktop.changes
+++ b/telegram-desktop.changes
@@ -1,3 +1,17 @@
+-------------------------------------------------------------------
+Sat Mar 25 11:06:57 UTC 2023 - Manfred Hollstein <manfred.h@gmx.net>
+
+- The new default compiler gcc13 on Tumbleweed is too new for
+  compiling tg_owt-master.zip; e.g. "uint8_t" is now defined in
+  <cstdint> which almost all source files don't include. Stick
+  with gcc12 on Tumbleweed for now and wait for an update of
+  tg_owt-master.zip
+
+-------------------------------------------------------------------
+Fri Mar 17 09:57:44 UTC 2023 - Manfred Hollstein <manfred.h@gmx.net>
+
+- compiler_upgrade is also needed on Leap 15.5
+
 -------------------------------------------------------------------
 Tue Feb 28 07:18:52 UTC 2023 - Manfred Hollstein <manfred.h@gmx.net>
 
diff --git a/telegram-desktop.spec b/telegram-desktop.spec
index fe25546..3a5a1a0 100644
--- a/telegram-desktop.spec
+++ b/telegram-desktop.spec
@@ -24,11 +24,16 @@
 %define __builder ninja
 
 # gcc10 or higher is required
-%if 0%{?suse_version} && ( 0%{?suse_version} < 1500 || ( 0%{?is_opensuse} && 0%{?suse_version} == 1500 && 0%{?sle_version} && 0%{?sle_version} <= 150400 ) )
+%if 0%{?suse_version} && ( 0%{?suse_version} < 1500 || ( 0%{?is_opensuse} && 0%{?suse_version} == 1500 && 0%{?sle_version} && 0%{?sle_version} <= 150500 ) )
 %bcond_without  compiler_upgrade
 %else
+%if 0%{?suse_version} > 01500
+# gcc13 is too new on Tumbleweed
+%bcond_without  compiler_downgrade
+%else
 %bcond_with     compiler_upgrade
 %endif
+%endif
 
 %define _dwz_low_mem_die_limit  40000000
 %define _dwz_max_die_limit     200000000
@@ -75,10 +80,16 @@ BuildRequires:  enchant-devel
 BuildRequires:  ffmpeg-devel
 BuildRequires:  freetype-devel
 %if %{with compiler_upgrade}
+BuildRequires:  gcc10
 BuildRequires:  gcc10-c++
 %else
+%if %{with compiler_downgrade}
+BuildRequires:  gcc12
+BuildRequires:  gcc12-c++
+%else
 BuildRequires:  gcc-c++
 %endif
+%endif
 BuildRequires:  glibc-devel
 BuildRequires:  libjpeg-devel
 BuildRequires:  liblz4-devel
@@ -227,6 +238,11 @@ mv tg_owt-master Libraries/tg_owt
 %if %{with compiler_upgrade}
 export CC=gcc-10
 export CXX=g++-10
+%else
+%if %{with compiler_downgrade}
+export CC=gcc-12
+export CXX=g++-12
+%endif
 %endif
 
 # Fix build failures due to not finding installed headers for xkbcommon and wayland-client