diff --git a/tools/versioner/tests/preprocessor/run.sh b/tools/versioner/tests/preprocessor/run.sh
index 1b0aae2..60e7024 100644
--- a/tools/versioner/tests/preprocessor/run.sh
+++ b/tools/versioner/tests/preprocessor/run.sh
@@ -1,4 +1,29 @@
-rm -rf out
 set -e
-versioner headers -i -o out
-diff -q -w -B out expected
+
+function run_test {
+  SRC=$1
+  DST=$2
+  rm -rf $2
+  versioner $1 -i -o $2
+  diff -q -w -B $2 expected
+}
+
+run_test headers out
+run_test headers/ out
+run_test headers out/
+run_test headers/ out/
+
+run_test `pwd`/headers out
+run_test `pwd`/headers/ out
+run_test `pwd`/headers out/
+run_test `pwd`/headers/ out/
+
+run_test headers `pwd`/out
+run_test headers/ `pwd`/out
+run_test headers `pwd`/out/
+run_test headers/ `pwd`/out/
+
+run_test `pwd`/headers `pwd`/out
+run_test `pwd`/headers/ `pwd`/out
+run_test `pwd`/headers `pwd`/out/
+run_test `pwd`/headers/ `pwd`/out/