diff --git a/build-aux/syntax-check.mk b/build-aux/syntax-check.mk
index 513c147cec..6b54f830f1 100644
--- a/build-aux/syntax-check.mk
+++ b/build-aux/syntax-check.mk
@@ -1502,6 +1502,14 @@ sc_po_check:
 	  rm -f $@-1 $@-2;						\
 	fi
 
+linguas_file = $(top_srcdir)/po/LINGUAS
+
+sc_linguas_sorting:
+	@sort -u $(linguas_file) > $@-1; \
+	diff -u -L $(linguas_file) -L $(linguas_file) $(linguas_file) $@-1 \
+	  || { echo "$(linguas_file) is not sorted correctly" 1>&2; exit 1; }; \
+	rm -f $@-1
+
 # #if WITH_... will evaluate to false for any non numeric string.
 # That would be flagged by using -Wundef, however gnulib currently
 # tests many undefined macros, and so we can't enable that option.