diff --git a/test/run b/test/run
index 2cee36f..7298e6a 100755
--- a/test/run
+++ b/test/run
@@ -55,6 +55,7 @@ set shell=/bin/bash
 source $PLUG_SRC
 VIMRC
 
+[ -z "$TMPDIR" ] && export TMPDIR=/tmp
 init
 if [ "$1" = '!' ]; then
   /usr/local/bin/vim -Nu /tmp/mini-vimrc -c 'Vader! workflow.vader' > /dev/null &&
diff --git a/test/workflow.vader b/test/workflow.vader
index 0e46d54..fdbee76 100644
--- a/test/workflow.vader
+++ b/test/workflow.vader
@@ -1036,6 +1036,11 @@ Execute (PlugSnapshot):
   AssertEqual 'PLUG_HOME=$TMPDIR/plugged', getline(7)
   AssertEqual 0, stridx(getline(9), 'cd $PLUG_HOME/seoul256.vim/ && git reset --hard')
   AssertEqual 0, stridx(getline(10), 'cd $PLUG_HOME/vim-emoji/ && git reset --hard')
+  AssertEqual 'sh', &filetype
+
+  execute 'PlugSnapshot' g:plug_home.'/snapshot.sh'
+  AssertEqual 'sh', &filetype
+  AssertEqual 'snapshot.sh', fnamemodify(expand('%'), ':t')
   q
 
 Execute (Cleanup):