diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c
index d9ef5c27ec86..058eba98bb2c 100644
--- a/cmd/zdb/zdb.c
+++ b/cmd/zdb/zdb.c
@@ -8430,7 +8430,7 @@ main(int argc, char **argv)
 	zfs_btree_verify_intensity = 3;
 
 	while ((c = getopt(argc, argv,
-	    "a:AB:bcCdDeEf:Fg:GhiI:klLmMo:Op:PqrRsSt:uU:vVx:XYyZz")) != -1) {
+	    "a:AB:bcCdDeEf:Fg:GhiI:klLmMo:Op:PqrRsSt:uU:vVx:XYyZz:")) != -1) {
 		switch (c) {
 		case 'b':
 		case 'c':
diff --git a/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_args_neg.ksh b/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_args_neg.ksh
index 06317bd518f7..54ec6cb24b47 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_args_neg.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zdb/zdb_args_neg.ksh
@@ -57,7 +57,7 @@ set -A args "create" "add" "destroy" "import fakepool" \
     "add raidz1 fakepool" "add raidz2 fakepool" \
     "setvprop" "blah blah" "-%" "--?" "-*" "-=" \
     "-j" "-n" "-o" "-p" "-p /tmp" \
-    "-t" "-w" "-z" "-E" "-H" "-I" "-J" "-K" \
+    "-t" "-w" "-E" "-H" "-I" "-J" "-K" \
     "-N" "-Q" "-R" "-T" "-W"
 
 log_assert "Execute zdb using invalid parameters."