diff --git a/lib/spack/docs/mirrors.rst b/lib/spack/docs/mirrors.rst
index 8f4eea1f8cd..4075421e123 100644
--- a/lib/spack/docs/mirrors.rst
+++ b/lib/spack/docs/mirrors.rst
@@ -162,7 +162,7 @@ your site.
 
 Once you have a mirror, you need to let spack know about it.  This is
 relatively simple.  First, figure out the URL for the mirror.  If it's
-a file, you can use a file URL like this one:
+a directory, you can use a file URL like this one:
 
 .. code-block:: none