diff --git a/packages/entity/src/behavior-components/expression.jsx b/packages/entity/src/behavior-components/expression.jsx
index 98be973..47a4bcd 100644
--- a/packages/entity/src/behavior-components/expression.jsx
+++ b/packages/entity/src/behavior-components/expression.jsx
@@ -273,6 +273,7 @@ const Expression = ({
               path: opPath,
               value: {
                 type: 'literal',
+                value: null,
               },
             });
           }
diff --git a/packages/entity/src/behavior-components/expression/invocation.jsx b/packages/entity/src/behavior-components/expression/invocation.jsx
index 2fafbe1..330a9a2 100644
--- a/packages/entity/src/behavior-components/expression/invocation.jsx
+++ b/packages/entity/src/behavior-components/expression/invocation.jsx
@@ -36,6 +36,7 @@ const Invocation = ({
                 path: argPath,
                 value: {
                   type: 'literal',
+                  value: null,
                 },
               });
               return;