Merge #12249 fix from 3.2
diff --git a/Doc/documenting/building.rst b/Doc/documenting/building.rst
index 19cf26b..dc1c6a0 100644
--- a/Doc/documenting/building.rst
+++ b/Doc/documenting/building.rst
@@ -14,6 +14,7 @@
 Luckily, a Makefile has been prepared so that on Unix, provided you have
 installed Python and Subversion, you can just run ::
 
+   cd Doc
    make html
 
 to check out the necessary toolset in the :file:`tools/` subdirectory and build