diff --git a/contributed_definitions/NXcg_polygon_set.nxdl.xml b/contributed_definitions/NXcg_polygon_set.nxdl.xml
index 31a71c5721..4969f2e83e 100644
--- a/contributed_definitions/NXcg_polygon_set.nxdl.xml
+++ b/contributed_definitions/NXcg_polygon_set.nxdl.xml
@@ -97,7 +97,7 @@ somewhat redundant as there is NXoff_geometry but easier to understand
         <doc>
              Integer used to distinguish polygons for explicit indexing.
         </doc>
-        <dimensions>
+        <dimensions rank="1">
             <dim index="1" value="c"/>
         </dimensions>
     </field>
diff --git a/contributed_definitions/NXstage_lab.nxdl.xml b/contributed_definitions/NXstage_lab.nxdl.xml
index e3c52b3ef9..7b916d2728 100644
--- a/contributed_definitions/NXstage_lab.nxdl.xml
+++ b/contributed_definitions/NXstage_lab.nxdl.xml
@@ -2,9 +2,9 @@
 <?xml-stylesheet type="text/xsl" href="nxdlformat.xsl"?>
 <!--
 # NeXus - Neutron and X-ray Common Data Format
-#
+# 
 # Copyright (C) 2014-2024 NeXus International Advisory Committee (NIAC)
-#
+# 
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
 # License as published by the Free Software Foundation; either
diff --git a/contributed_definitions/NXsubsampling_filter.nxdl.xml b/contributed_definitions/NXsubsampling_filter.nxdl.xml
index f4e6577d5e..ea378eab39 100644
--- a/contributed_definitions/NXsubsampling_filter.nxdl.xml
+++ b/contributed_definitions/NXsubsampling_filter.nxdl.xml
@@ -2,9 +2,9 @@
 <?xml-stylesheet type="text/xsl" href="nxdlformat.xsl"?>
 <!--
 # NeXus - Neutron and X-ray Common Data Format
-#
+# 
 # Copyright (C) 2014-2024 NeXus International Advisory Committee (NIAC)
-#
+# 
 # This library is free software; you can redistribute it and/or
 # modify it under the terms of the GNU Lesser General Public
 # License as published by the Free Software Foundation; either
diff --git a/requirements.txt b/requirements.txt
index 4b6ab51d58..8ba01346dd 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 # Prepare for Documentation
 lxml
 pyyaml
-nyaml
+nyaml==0.0.8
 
 # Documentation building
 sphinx>=5