diff --git a/setup.py b/setup.py
index 1267e29..812d5aa 100755
--- a/setup.py
+++ b/setup.py
@@ -159,6 +159,10 @@ def main():
           data_files=data_files)
 
 if __name__ == '__main__':
+    # This script assumes it is being run from the top-level project directory
+    # and all filenames are relative to that. This may not always be the case,
+    # so lets make sure we are in that working directory before continuing.
+    os.chdir(os.path.dirname(__file__))
     main()
 
 # vim: set filetype=python sts=4 sw=4 et si :