diff --git a/run_tests.py b/run_tests.py
index 74407ce4..e029b9a6 100755
--- a/run_tests.py
+++ b/run_tests.py
@@ -234,7 +234,7 @@ def add_prefix(path):
     else:
         input_prefix = ""
     path = input_prefix + path
-    path = os.path.normpath(path)
+    path = os.path.abspath(path)
     return path