diff --git a/core/datamodel.core.xml b/core/datamodel.core.xml
index c75b780b48..baca05011b 100644
--- a/core/datamodel.core.xml
+++ b/core/datamodel.core.xml
@@ -126,7 +126,7 @@
         <field id="message" xsi:type="AttributeText">
           <sql>message</sql>
           <default_value/>
-          <is_null_allowed>true</is_null_allowed>
+          <is_null_allowed>false</is_null_allowed>
         </field>
         <field id="icon" xsi:type="AttributeImage">
           <sql>icon</sql>