diff --git a/coverage.sh b/coverage.sh
index 0e7cba0..3cee41d 100755
--- a/coverage.sh
+++ b/coverage.sh
@@ -184,6 +184,12 @@ for f in "/tmp/debian-$dist-debootstrap/etc/shells" "/tmp/debian-$dist-mm/etc/sh
 	sort -o "\$f" "\$f"
 done
 
+# workaround for https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=917773
+awk -v FS=: -v OFS=: -v SDE=\$SOURCE_DATE_EPOCH '{ print \$1,\$2,int(SDE/60/60/24),\$4,\$5,\$6,\$7,\$8,\$9 }' < /tmp/debian-$dist-mm/etc/shadow > /tmp/debian-$dist-mm/etc/shadow.bak
+mv /tmp/debian-$dist-mm/etc/shadow.bak /tmp/debian-$dist-mm/etc/shadow
+awk -v FS=: -v OFS=: -v SDE=\$SOURCE_DATE_EPOCH '{ print \$1,\$2,int(SDE/60/60/24),\$4,\$5,\$6,\$7,\$8,\$9 }' < /tmp/debian-$dist-mm/etc/shadow- > /tmp/debian-$dist-mm/etc/shadow-.bak
+mv /tmp/debian-$dist-mm/etc/shadow-.bak /tmp/debian-$dist-mm/etc/shadow-
+
 # check if the file content differs
 diff --no-dereference --brief --recursive /tmp/debian-$dist-debootstrap /tmp/debian-$dist-mm