diff --git a/runtime/indent/Makefile b/runtime/indent/Makefile
index 3791f33..1917e46 100644
--- a/runtime/indent/Makefile
+++ b/runtime/indent/Makefile
@@ -1,13 +1,14 @@
 # Portable Makefile for running indent tests.
 
 VIM = vim
+VIMRUNTIME = ..
 
 # Run the tests that didn't run yet or failed previously.
 # If a test succeeds a testdir/*.out file will be written.
 # If a test fails a testdir/*.fail file will be written.
 test:
-	$(VIM) --clean --not-a-term -u testdir/runtest.vim
+	VIMRUNTIME=$(VIMRUNTIME) $(VIM) --clean --not-a-term -u testdir/runtest.vim
 
 
 clean:
-	$(VIM) --clean --not-a-term -u testdir/cleantest.vim
+	VIMRUNTIME=$(VIMRUNTIME) $(VIM) --clean --not-a-term -u testdir/cleantest.vim