diff --git a/tests/generate.zsh b/tests/generate.zsh
index 811abae..259ea75 100755
--- a/tests/generate.zsh
+++ b/tests/generate.zsh
@@ -63,7 +63,7 @@ fi
 git add -- $fname
 
 # Buffer
-exec > >(tee $fname)
+exec > >(tee -a $fname)
 print -n 'BUFFER='
 if [[ $buffer != (#s)[$'\t -~']#(#e) ]]; then
   print -r -- ${(qqqq)buffer}