diff --git a/tools/check-source.sh b/tools/check-source.sh
index e3cf49d72c..74ca99b93d 100755
--- a/tools/check-source.sh
+++ b/tools/check-source.sh
@@ -6,7 +6,7 @@ failed=0
 
 # Ignore files where rules may be violated within macro definitions.
 texfiles=$(ls *.tex | grep -v macros.tex | grep -v layout.tex | grep -v tables.tex)
-texlibdesc="support.tex concepts.tex diagnostics.tex memory.tex meta.tex utilities.tex strings.tex containers.tex iterators.tex ranges.tex algorithms.tex numerics.tex time.tex locales.tex iostreams.tex regex.tex threads.tex"
+texlibdesc="support.tex concepts.tex diagnostics.tex memory.tex meta.tex utilities.tex strings.tex containers.tex iterators.tex ranges.tex algorithms.tex numerics.tex time.tex locales.tex iostreams.tex threads.tex"
 texlib="lib-intro.tex $texlibdesc"
 
 # Filter that reformats the error message as a "workflow command",