diff --git a/src/betterproto/__init__.py b/src/betterproto/__init__.py
index 8eee6f4c..7b76e730 100644
--- a/src/betterproto/__init__.py
+++ b/src/betterproto/__init__.py
@@ -968,9 +968,9 @@ def dump(self, stream: "SupportsWrite[bytes]", delimit: bool = False) -> None:
                 field_name=field_name, meta=meta
             )
 
-            if value == self._get_field_default(field_name) and not (
+            if not (
                 selected_in_group or serialize_empty or include_default_value_for_oneof
-            ):
+            ) and value == self._get_field_default(field_name):
                 # Default (zero) values are not serialized. Two exceptions are
                 # if this is the selected oneof item or if we know we have to
                 # serialize an empty message (i.e. zero value was explicitly
@@ -1074,9 +1074,9 @@ def __len__(self) -> int:
                 field_name=field_name, meta=meta
             )
 
-            if value == self._get_field_default(field_name) and not (
+            if not (
                 selected_in_group or serialize_empty or include_default_value_for_oneof
-            ):
+            ) and value == self._get_field_default(field_name):
                 # Default (zero) values are not serialized. Two exceptions are
                 # if this is the selected oneof item or if we know we have to
                 # serialize an empty message (i.e. zero value was explicitly