diff --git a/Assets/VRM/UniJSON/Scripts/GenericCast.cs b/Assets/VRM/UniJSON/Scripts/GenericCast.cs
index 890172611..fafc29bd2 100644
--- a/Assets/VRM/UniJSON/Scripts/GenericCast.cs
+++ b/Assets/VRM/UniJSON/Scripts/GenericCast.cs
@@ -56,10 +56,7 @@ namespace UniJSON
             }
             else
             {
-                return (Func<S, T>)((S s) =>
-                {
-                    return (T)mi.Invoke(null, new object[] { s });
-                });
+                return GenericInvokeCallFactory.StaticFunc<S, T>(mi);
             }
         }
 
diff --git a/Assets/VRM/UniJSON/Scripts/JsonSchemaValidator/JsonEnumValidator.cs b/Assets/VRM/UniJSON/Scripts/JsonSchemaValidator/JsonEnumValidator.cs
index 4cd4ec7d8..2559e3ee6 100644
--- a/Assets/VRM/UniJSON/Scripts/JsonSchemaValidator/JsonEnumValidator.cs
+++ b/Assets/VRM/UniJSON/Scripts/JsonSchemaValidator/JsonEnumValidator.cs
@@ -319,9 +319,11 @@ namespace UniJSON
                         var mi = typeof(Enum).GetMethods(BindingFlags.Static | BindingFlags.Public).First(
                             x => x.Name == "Parse" && x.GetParameters().Length == 3
                             );
+
+                        var enumParse = GenericInvokeCallFactory.StaticFunc<Type, string, bool, object>(mi);
                         s_d = x =>
                         {
-                            var enumValue = mi.Invoke(null, new object[] { typeof(U), x.GetString(), true });
+                            var enumValue = enumParse(typeof(U), x.GetString(), true);
                             return GenericCast<object, U>.Cast(enumValue);
                         };
                     }
diff --git a/Assets/VRM/UniJSON/Scripts/JsonSchemaValidator/JsonObjectValidator.cs b/Assets/VRM/UniJSON/Scripts/JsonSchemaValidator/JsonObjectValidator.cs
index e0a026014..2c584e181 100644
--- a/Assets/VRM/UniJSON/Scripts/JsonSchemaValidator/JsonObjectValidator.cs
+++ b/Assets/VRM/UniJSON/Scripts/JsonSchemaValidator/JsonObjectValidator.cs
@@ -338,7 +338,7 @@ namespace UniJSON
                         BindingFlags.Static | BindingFlags.NonPublic)
                         ;
                     var g = mi.MakeGenericMethod(fi.FieldType);
-                    return (FieldValidator)g.Invoke(null, new object[] { fi });
+                    return GenericInvokeCallFactory.StaticFunc<FieldInfo, FieldValidator>(g)(fi);
                 }
 
                 static FieldValidator _CreateFieldValidator<U>(FieldInfo fi)
@@ -498,7 +498,7 @@ namespace UniJSON
                     var mi = typeof(Serializer).GetMethod("_CreateFieldSerializer",
                         BindingFlags.Static | BindingFlags.NonPublic);
                     var g = mi.MakeGenericMethod(fi.FieldType);
-                    return (FieldSerializer)g.Invoke(null, new object[] { fi });
+                    return GenericInvokeCallFactory.StaticFunc<FieldInfo, FieldSerializer>(g)(fi);
                 }
 
                 static FieldSerializer _CreateFieldSerializer<U>(FieldInfo fi)