diff --git a/src/testdir/screendump.vim b/src/testdir/screendump.vim
index 4015419..1630dfa 100644
--- a/src/testdir/screendump.vim
+++ b/src/testdir/screendump.vim
@@ -113,6 +113,10 @@
   let reference = 'dumps/' . a:filename . '.dump'
   let testfile = 'failed/' . a:filename . '.dump'
 
+  " Redraw to execut the code that updates the screen.  Otherwise we get the
+  " text and attributes only from the internal buffer.
+  redraw
+
   let did_mkdir = 0
   if !isdirectory('failed')
     let did_mkdir = 1