diff -Nru s390-tools-1.34.0/debian/changelog s390-tools-1.34.0/debian/changelog
--- s390-tools-1.34.0/debian/changelog	2018-02-21 13:44:02.000000000 -0300
+++ s390-tools-1.34.0/debian/changelog	2018-04-30 11:20:25.000000000 -0300
@@ -1,3 +1,10 @@
+s390-tools (1.34.0-0ubuntu8.6) xenial; urgency=medium
+
+  * zz-zipl: Do not run if non-optional initrds don't exist yet (LP: #1766727)
+    - Backport of the fix for bionic by Adam Conrad.
+
+ -- Thadeu Lima de Souza Cascardo <cascardo@canonical.com>  Mon, 30 Apr 2018 11:20:25 -0300
+
 s390-tools (1.34.0-0ubuntu8.5) xenial; urgency=medium
 
   * Correct postinst, which cleans up erroneous directory from
diff -Nru s390-tools-1.34.0/debian/kernel/zz-zipl s390-tools-1.34.0/debian/kernel/zz-zipl
--- s390-tools-1.34.0/debian/kernel/zz-zipl	2016-02-14 15:47:22.000000000 -0200
+++ s390-tools-1.34.0/debian/kernel/zz-zipl	2018-04-30 11:19:01.000000000 -0300
@@ -16,6 +16,24 @@
 
 if [ -f /etc/zipl.conf ]
 then
+    for initrd in $(awk '
+      function emit() {
+        if (optional == "0" && ramdisk != "") {
+          print(ramdisk);
+        };
+        ramdisk="";
+        optional="0";
+      }
+      /^optional[ 	]*=/	{ optional=$0; sub("^optional[ 	]*=[ 	]*", "", optional); }
+      /^ramdisk[ 	]*=/	{ ramdisk=$0; sub("^ramdisk[ 	]*=[ 	]*", "", ramdisk); }
+      /^\[/			{ emit(); }
+      END			{ emit(); }
+      ' < /etc/zipl.conf); do
+        if [ ! -f "$initrd" ]; then
+            echo "Not invoking zipl: initrd doesn't exist yet" >&2
+            exit 0
+        fi
+    done
     zipl </dev/null >&2
 else
     echo "WARNING, not invoking zipl: /etc/zipl.conf not found" >&2