diff --git a/serde/de.py b/serde/de.py
index be905d8..90dc35e 100644
--- a/serde/de.py
+++ b/serde/de.py
@@ -803,6 +803,9 @@ reuse_instances=reuse_instances)) if data.get("f") is not None else None'
         value_arg = arg[0]
         if arg.iterbased:
             exists = f"{arg.data} is not None"
+        elif arg.alias:
+            aliases = (f'"{s}"' for s in [arg.name, *arg.alias])
+            exists = f'_exists_by_aliases({arg.datavar}, [{",".join(aliases)}])'
         else:
             exists = f'{arg.datavar}.get("{arg.conv_name()}") is not None'
         return f"({self.render(value_arg)}) if {exists} else None"