diff --git a/m4 b/m4
index 4f3c17eb4..c2d9bd4ee 160000
--- a/m4
+++ b/m4
@@ -1 +1 @@
-Subproject commit 4f3c17eb458afecdc57df1be498c1d4813acd675
+Subproject commit c2d9bd4ee0589d49320e0ad73785021f54283091