diff --git a/runtime/indent/Makefile b/runtime/indent/Makefile
index fa81db0..3791f33 100644
--- a/runtime/indent/Makefile
+++ b/runtime/indent/Makefile
@@ -6,8 +6,8 @@
 # If a test succeeds a testdir/*.out file will be written.
 # If a test fails a testdir/*.fail file will be written.
 test:
-	$(VIM) --not-a-term -u testdir/runtest.vim
+	$(VIM) --clean --not-a-term -u testdir/runtest.vim
 
 
 clean:
-	$(VIM) --not-a-term -u testdir/cleantest.vim
+	$(VIM) --clean --not-a-term -u testdir/cleantest.vim
diff --git a/runtime/indent/testdir/runtest.vim b/runtime/indent/testdir/runtest.vim
index 5d36512..1cc0d3f 100644
--- a/runtime/indent/testdir/runtest.vim
+++ b/runtime/indent/testdir/runtest.vim
@@ -1,4 +1,6 @@
-" Runs all the indent tests for which there is no .out file
+" Runs all the indent tests for which there is no .out file.
+"
+" Current directory must be runtime/indent.
 
 set nocp
 filetype indent on