diff --git a/autogen.sh b/autogen.sh
index f311080..4d4d15a 100755
--- a/autogen.sh
+++ b/autogen.sh
@@ -3,4 +3,5 @@ set -e
 aclocal -I m4
 autoheader
 autoconf
+rm -f m4/*~ 2>/dev/null || true
 sha256sum configure.ac aclocal.m4 libqpdf/qpdf/qpdf-config.h.in m4/* >| autofiles.sums