diff --git a/src/testdir/test64.in b/src/testdir/test64.in
index 4fdbcf7..a7b5794 100644
--- a/src/testdir/test64.in
+++ b/src/testdir/test64.in
@@ -338,6 +338,7 @@
 :call add(tl, [2, '^\%(.*bar\)\@!.*\zsfoo', ' bar foo '])
 :call add(tl, [2, '^\%(.*bar\)\@!.*\zsfoo', ' foo bar '])
 :call add(tl, [2, '^\%(.*bar\)\@!.*\zsfoo', ' foo xxx ', 'foo'])
+:call add(tl, [2, '[ ]\@!\p\%([ ]\@!\p\)*:', 'implicit mappings:', 'mappings:'])
 :"
 :"""" Combining different tests and features
 :call add(tl, [2, '[[:alpha:]]\{-2,6}', '787abcdiuhsasiuhb4', 'ab'])
diff --git a/src/testdir/test64.ok b/src/testdir/test64.ok
index d1f4113..8aa5a60 100644
--- a/src/testdir/test64.ok
+++ b/src/testdir/test64.ok
@@ -770,6 +770,9 @@
 OK 0 - ^\%(.*bar\)\@!.*\zsfoo
 OK 1 - ^\%(.*bar\)\@!.*\zsfoo
 OK 2 - ^\%(.*bar\)\@!.*\zsfoo
+OK 0 - [ ]\@!\p\%([ ]\@!\p\)*:
+OK 1 - [ ]\@!\p\%([ ]\@!\p\)*:
+OK 2 - [ ]\@!\p\%([ ]\@!\p\)*:
 OK 0 - [[:alpha:]]\{-2,6}
 OK 1 - [[:alpha:]]\{-2,6}
 OK 2 - [[:alpha:]]\{-2,6}