diff --git a/esmvalcore/cmor/table.py b/esmvalcore/cmor/table.py
index ca2037a2eb..07a1ed86bf 100644
--- a/esmvalcore/cmor/table.py
+++ b/esmvalcore/cmor/table.py
@@ -733,7 +733,7 @@ def get_variable(self, table, short_name, derived=False):
 
         if var_info:
             mip_info = self.get_table(table)
-            var_info.copy()
+            var_info = var_info.copy()
             if mip_info:
                 var_info.frequency = mip_info.frequency
         return var_info
@@ -773,8 +773,8 @@ def _read_coordinate(self, value):
 
     def _read_variable(self, short_name, frequency):
         var = super()._read_variable(short_name, frequency)
-        var.modeling_realm = None
         var.frequency = None
+        var.modeling_realm = None
         return var
 
 
@@ -872,7 +872,7 @@ def _read_table_file(self, table_file, table=None):
                     self.coords[value] = self._read_coordinate(value)
                     continue
                 elif key == 'variable_entry':
-                    table[value] = self._read_variable(value, None)
+                    table[value] = self._read_variable(value, '')
                     continue
                 if not self._read_line():
                     return