diff --git a/shared/sx/helpers.py b/shared/sx/helpers.py
index ead0b17..4acd87f 100644
--- a/shared/sx/helpers.py
+++ b/shared/sx/helpers.py
@@ -77,7 +77,7 @@ def _as_sx(val: Any) -> SxExpr | None:
     if not val:
         return None
     if isinstance(val, SxExpr):
-        return val
+        return val if val.source else None
     html = str(val)
     escaped = html.replace("\\", "\\\\").replace('"', '\\"')
     return SxExpr(f'(~rich-text :html "{escaped}")')
@@ -376,7 +376,10 @@ def _build_component_ast(__name: str, **kwargs: Any) -> list:
         elif isinstance(val, SxExpr):
             # SxExpr values need to be parsed into AST
             from .parser import parse
-            ast.append(parse(val.source))
+            if not val.source:
+                ast.append(NIL)
+            else:
+                ast.append(parse(val.source))
         else:
             ast.append(val)
     return ast