diff --git a/esmvalcore/cmor/tables/custom/CMOR_vmrh2o.dat b/esmvalcore/cmor/tables/custom/CMOR_vmrh2o.dat
new file mode 100644
index 0000000000..925293b49d
--- /dev/null
+++ b/esmvalcore/cmor/tables/custom/CMOR_vmrh2o.dat
@@ -0,0 +1,22 @@
+!============
+variable_entry:    vmrh2o
+!============
+modeling_realm:    atmos
+!----------------------------------
+! Variable attributes:
+!----------------------------------
+standard_name:
+units:             mole mole-1
+cell_methods:      time: mean
+cell_measures:     area: areacella
+long_name:         Water Vapour Volume Mixing Ratio
+comment:           
+!----------------------------------
+! Additional variable information:
+!----------------------------------
+dimensions:        longitude latitude plevs time
+type:              real
+valid_min:         0.0
+valid_max:         1.0
+!----------------------------------
+!