diff --git a/cfdm/read_write/netcdf/netcdfwrite.py b/cfdm/read_write/netcdf/netcdfwrite.py
index 19db6daaa..d8fdd0b56 100644
--- a/cfdm/read_write/netcdf/netcdfwrite.py
+++ b/cfdm/read_write/netcdf/netcdfwrite.py
@@ -5008,7 +5008,7 @@ def _file_io_iteration(
         # ------------------------------------------------------------
         # Set possible versions
         # ------------------------------------------------------------
-        for version in ("1.6", "1.7", "1.8", "1.9", "1.10"):
+        for version in ("1.6", "1.7", "1.8", "1.9", "1.10", "1.11"):
             g["CF-" + version] = Version(version)
 
         if extra_write_vars: