diff --git a/ChangeLog b/ChangeLog
index 0e33f9d..c003d4e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2020-06-28  John Ericson  <john.ericson@obsidian.systems>
+
+	* config.sub (s390, s390x): Use 'ibm' vendor default, but allow
+	overrides.
+
 2020-06-27  John Ericson  <john.ericson@obsidian.systems>
 
 	* config.sub: Allow CPU to influence vendor defaulting too.
diff --git a/config.sub b/config.sub
index b2c4a19..9ab201a 100755
--- a/config.sub
+++ b/config.sub
@@ -1763,6 +1763,9 @@ case $vendor in
 			*-os400*)
 				vendor=ibm
 				;;
+			s390-* | s390x-*)
+				vendor=ibm
+				;;
 			*-ptx*)
 				vendor=sequent
 				;;
diff --git a/testsuite/config-sub.data b/testsuite/config-sub.data
index c4fe79d..d9639bc 100644
--- a/testsuite/config-sub.data
+++ b/testsuite/config-sub.data
@@ -581,10 +581,12 @@ rs6000						rs6000-ibm-aix
 rx-linux					rx-unknown-linux-gnu
 rx						rx-unknown-none
 s12z						s12z-unknown-none
-s390						s390-unknown-none
-s390x						s390x-unknown-none
-s390-linux					s390-unknown-linux-gnu
-s390x-linux					s390x-unknown-linux-gnu
+s390						s390-ibm-none
+s390x						s390x-ibm-none
+s390-linux					s390-ibm-linux-gnu
+s390x-linux					s390x-ibm-linux-gnu
+s390-busybox-linux				s390-busybox-linux-gnu
+s390x-busybox-linux				s390x-busybox-linux-gnu
 s390-ibm-zvmoe					s390-ibm-zvmoe
 s390x-ibm-zvmoe					s390x-ibm-zvmoe
 sa29200						a29k-amd-udi