diff --git a/poem-openapi-derive/src/utils.rs b/poem-openapi-derive/src/utils.rs
index 2fe6de43a9..f64e8d0c98 100644
--- a/poem-openapi-derive/src/utils.rs
+++ b/poem-openapi-derive/src/utils.rs
@@ -191,13 +191,13 @@ pub(crate) fn create_object_name(
             use ::std::convert::From;
             let mut name = ::std::string::String::from(#name);
 
-            name.push('<');
+            name.push('_');
             name.push_str(&<#first as #crate_name::types::Type>::name());
             #(
                 name.push_str(", ");
                 name.push_str(&<#tail as #crate_name::types::Type>::name());
             )*
-            name.push('>');
+            name.push('_');
 
             name
         })
diff --git a/poem-openapi/src/types/maybe_undefined.rs b/poem-openapi/src/types/maybe_undefined.rs
index 48eda7755e..5604d1ce1c 100644
--- a/poem-openapi/src/types/maybe_undefined.rs
+++ b/poem-openapi/src/types/maybe_undefined.rs
@@ -151,6 +151,12 @@ impl<T> MaybeUndefined<T> {
         matches!(self, MaybeUndefined::Value(_))
     }
 
+    /// Returns true if the `MaybeUndefined<T>` contains value or is null.
+    #[inline]
+    pub const fn is_value_or_null(&self) -> bool {
+        matches!(self, MaybeUndefined::Value(_)) || matches!(self, MaybeUndefined::Null)
+    }
+
     /// Returns `None` if the the `MaybeUndefined<T>` is
     /// `undefined` or `null`, otherwise returns `Some(&T)`.
     #[inline]
diff --git a/poem-openapi/tests/object.rs b/poem-openapi/tests/object.rs
index 975f7badb7..bc2e389589 100644
--- a/poem-openapi/tests/object.rs
+++ b/poem-openapi/tests/object.rs
@@ -1,3 +1,4 @@
+
 use poem_openapi::{
     registry::{MetaExternalDocument, MetaSchema, MetaSchemaRef, Registry},
     types::{Example, ParseFromJSON, ToJSON, Type},
@@ -45,7 +46,7 @@ fn generics() {
 
     assert_eq!(
         <Obj<i32, i64>>::name(),
-        "Obj<integer(int32), integer(int64)>"
+        "Obj_integer(int32), integer(int64)_"
     );
     let meta = get_meta::<Obj<i32, i64>>();
     assert_eq!(meta.properties[0].1.unwrap_inline().ty, "integer");
@@ -56,7 +57,7 @@ fn generics() {
 
     assert_eq!(
         <Obj<f32, f64>>::name(),
-        "Obj<number(float), number(double)>"
+        "Obj_number(float), number(double)_"
     );
     let meta = get_meta::<Obj<f32, f64>>();
     assert_eq!(meta.properties[0].1.unwrap_inline().ty, "number");
diff --git a/poem-openapi/tests/union.rs b/poem-openapi/tests/union.rs
index a784d3756f..3786a46041 100644
--- a/poem-openapi/tests/union.rs
+++ b/poem-openapi/tests/union.rs
@@ -514,11 +514,11 @@ async fn generics() {
 
     assert_eq!(
         <MyObj<i32, i64>>::schema_ref(),
-        MetaSchemaRef::Reference("MyObj<integer(int32), integer(int64)>".to_string())
+        MetaSchemaRef::Reference("MyObj_integer(int32), integer(int64)_".to_string())
     );
     assert_eq!(
         <MyObj<f32, f64>>::schema_ref(),
-        MetaSchemaRef::Reference("MyObj<number(float), number(double)>".to_string())
+        MetaSchemaRef::Reference("MyObj_number(float), number(double)_".to_string())
     );
 
     assert_eq!(schema_i32_i64.any_of[0], i32::schema_ref());