diff --git a/app/models/data_digest_template.rb b/app/models/data_digest_template.rb
index f2bae517..86fead45 100644
--- a/app/models/data_digest_template.rb
+++ b/app/models/data_digest_template.rb
@@ -92,6 +92,7 @@ def columns_config=(value)
     value = value.presence
     value = JSON.parse(value) if value.is_a?(String)
     value = Array.wrap(value)
+    value = nil if value == self.class::DEFAULT_COLUMN_CONFIG
     super(value)
   end