diff --git a/internal_tests/pytests/grid_stat/test_grid_stat_wrapper.py b/internal_tests/pytests/grid_stat/test_grid_stat_wrapper.py
index 76f25e6d0..017731ed7 100644
--- a/internal_tests/pytests/grid_stat/test_grid_stat_wrapper.py
+++ b/internal_tests/pytests/grid_stat/test_grid_stat_wrapper.py
@@ -478,6 +478,9 @@ def test_handle_climo_file_variables(metplus_config, config_overrides,
         ({'GRID_STAT_CLIMO_MEAN_DAY_INTERVAL': '30', },
          {'METPLUS_CLIMO_MEAN_DICT': 'climo_mean = {day_interval = 30;}'}),
 
+        ({'GRID_STAT_CLIMO_MEAN_DAY_INTERVAL': 'NA', },
+         {'METPLUS_CLIMO_MEAN_DICT': 'climo_mean = {day_interval = NA;}'}),
+
         ({'GRID_STAT_CLIMO_MEAN_HOUR_INTERVAL': '12', },
          {'METPLUS_CLIMO_MEAN_DICT': 'climo_mean = {hour_interval = 12;}'}),
 
diff --git a/metplus/wrappers/command_builder.py b/metplus/wrappers/command_builder.py
index 05b66f89b..dc834c840 100755
--- a/metplus/wrappers/command_builder.py
+++ b/metplus/wrappers/command_builder.py
@@ -1499,7 +1499,7 @@ def handle_climo_dict(self):
             }),
             'time_interp_method': ('string', 'remove_quotes,uppercase'),
             'match_month': ('bool', 'uppercase'),
-            'day_interval': 'int',
+            'day_interval': ('string', 'remove_quotes,uppercase'),
             'hour_interval': 'int',
             'file_type': ('string', 'remove_quotes'),
         }