diff --git a/cppad.spec b/cppad.spec
index 941ff36..f3f34d5 100644
--- a/cppad.spec
+++ b/cppad.spec
@@ -90,15 +90,32 @@ echo 'data = [ ]'         >> CppAD-%{version}/xrst.toml
 #
 # CppAD-%%{version}/build/html
 mkdir CppAD-%{version}/build
+# There is a bug in the version of python3-pygments used by fedora 37.
+# The code below checks if that is the only warning printed. 
+# This is not necessary with fedora 38 or later.
 xrst --version
-xrst \
+if xrst \
    --config_file CppAD-%{version}/xrst.toml \
    --local_toc \
    --target html \
    --html_theme sphinx_rtd_theme \
    --index_page_name user_guide \
    --group_list default app \
-   --suppress_spell_warnings
+   --suppress_spell_warnings 2> xrst.err
+then
+   echo 'xrst: OK'
+else
+   sed -i xrst.err \
+      -e '/WARNING: Could not lex literal_block as "cpp"/d' \
+      -e '/Warning: see system command message above./d' \
+      -e '/xrst: See warnings above/d' \
+      -e '/^ *$/d'
+   if [ -s xrst.err ]
+   then
+      cat xrst.err
+      exit 1
+   fi
+fi
 #
 # remove hidden files not needed for viewing documentation
 rm CppAD-%{version}/build/html/.buildinfo
@@ -261,6 +278,10 @@ make %{?_smp_mflags} check
 # This enables one to check that the necessary files are installed.
 # ----------------------------------------------------------------------------
 %changelog
+* Sun Feb 19 2023 Brad Bell <bradbell at seanet dot com> - 20230000.0-1
+- Check the xrst stderr output to make sure it only contains warning
+- for bug in the version of python3-pygments on fedora 37.
+
 * Sun Jan 29 2023 Brad Bell <bradbell at seanet dot com> - 20230000.0-1
 - Move libcppad_lib.so to main package (fixes a fedpkg lint error).
 - Fix comment about where doc files come from.