diff --git a/gcc.spec b/gcc.spec
index d12e881..74d2c65 100644
--- a/gcc.spec
+++ b/gcc.spec
@@ -1,10 +1,11 @@
+%global source_date_epoch_from_changelog 1
 %global DATE 20240719
 %global gitrev a985e3068a6f8045f8a6f2d2d5ae75f5eb0a8767
 %global gcc_version 11.5.0
 %global gcc_major 11
 # Note, gcc_release must be integer, if you want to add suffixes to
 # %%{release}, append them after %%{gcc_release} on Release: line.
-%global gcc_release 8
+%global gcc_release 9
 %global nvptx_tools_gitrev 5f6f343a302d620b0868edab376c00b15741e39e
 %global newlib_cygwin_gitrev 50e2a63b04bdd018484605fbb954fd1bd5147fa0
 %global _unpackaged_files_terminate_build 0
@@ -1831,9 +1832,9 @@ mv -f %{buildroot}%{_prefix}/%{_lib}/libstdc++*gdb.py* \
       %{buildroot}%{_datadir}/gdb/auto-load/%{_prefix}/%{_lib}/
 pushd ../libstdc++-v3/python
 for i in `find . -name \*.py`; do
-  touch -r $i %{buildroot}%{_prefix}/share/gcc-%{gcc_major}/python/$i
+  touch -d @$SOURCE_DATE_EPOCH %{buildroot}%{_prefix}/share/gcc-%{gcc_major}/python/$i
 done
-touch -r hook.in %{buildroot}%{_datadir}/gdb/auto-load/%{_prefix}/%{_lib}/libstdc++*gdb.py
+touch -d @$SOURCE_DATE_EPOCH %{buildroot}%{_datadir}/gdb/auto-load/%{_prefix}/%{_lib}/libstdc++*gdb.py
 popd
 for f in `find %{buildroot}%{_prefix}/share/gcc-%{gcc_major}/python/ \
 	       %{buildroot}%{_datadir}/gdb/auto-load/%{_prefix}/%{_lib}/ -name \*.py`; do
@@ -3612,6 +3613,9 @@ end
 %endif
 
 %changelog
+* Fri Jun 27 2025 Siddhesh Poyarekar <siddhesh@redhat.com> 11.5.0-9
+- Pin modification time for python files to SOURCE_DATE_EPOCH (RHEL-100148).
+
 * Mon Jun 23 2025 Siddhesh Poyarekar <siddhesh@redhat.com> - 11.5.0-8
 - Sync libstdc++ pretty printers to latest GTS (RHEL-81975)