diff --git a/spack.changes b/spack.changes
index 15d7b6c..97327ea 100644
--- a/spack.changes
+++ b/spack.changes
@@ -1,3 +1,11 @@
+-------------------------------------------------------------------
+Mon Jan  6 19:01:00 UTC 2025 - Egbert Eich <eich@suse.com>
+
+- Work towards a reproducible doc build (boo#1235144):
+  When building documentation, hard code:
+  * year for license.
+  * cpu count dependent settings.
+
 -------------------------------------------------------------------
 Fri Jan  3 13:40:08 UTC 2025 - Egbert Eich <eich@suse.com>
 
diff --git a/spack.spec b/spack.spec
index 5b6226a..d39d622 100644
--- a/spack.spec
+++ b/spack.spec
@@ -226,6 +226,12 @@ for i in share/spack/setup-env.*; do
 done
 %else
 cp %{S:5} lib/spack/docs/
+# For building docs make build reproducible:
+# - hard code year in license checker
+year=$(sed -ne "/Copyright/s@.*\([0-9]\{4\}\).*@\1@p" %{_sourcedir}/%{name}.spec)
+sed -ie "/^latest_year/s@\(.* = \).*@\1${year}@" lib/spack/spack/cmd/license.py
+# - hard code cpu count dependent settings
+sed -ie "/max_cpus.* =\|build_jobs/s@cpus_available()@8@" lib/spack/spack/config.py
 %endif
 
 %build