diff --git a/src/testdir/test31.in b/src/testdir/test31.in
index b00c760..7dc2334 100644
--- a/src/testdir/test31.in
+++ b/src/testdir/test31.in
@@ -63,6 +63,12 @@
 :" write "testtext 1"
 A 3:close!
 :w >>test.out
+:set nohidden
+:" test ":all!" hides changed buffer; write "testtext 2 2 2"
+:sp Xtest4
+GA 4:all!
+:1wincmd w
+:w >>test.out
 :qa!
 ENDTEST
 
diff --git a/src/testdir/test31.ok b/src/testdir/test31.ok
index 3311ad5..185bdc7 100644
--- a/src/testdir/test31.ok
+++ b/src/testdir/test31.ok
@@ -9,3 +9,4 @@
 testtext 1
 testtext 3 3 3
 testtext 1
+testtext 2 2 2