diff --git a/src/Unchase.Swashbuckle.AspNetCore.Extensions/Extensions/EnumTypeExtensions.cs b/src/Unchase.Swashbuckle.AspNetCore.Extensions/Extensions/EnumTypeExtensions.cs
index fb7bcdb..d0e81f6 100644
--- a/src/Unchase.Swashbuckle.AspNetCore.Extensions/Extensions/EnumTypeExtensions.cs
+++ b/src/Unchase.Swashbuckle.AspNetCore.Extensions/Extensions/EnumTypeExtensions.cs
@@ -211,22 +211,24 @@ internal static string AddEnumValuesDescription(
                 return null;
             }
 
+            var enumElements = schema.Enum.Where(element => !(element is OpenApiNull)).ToArray();
+
             if (!schema.Extensions.ContainsKey(xEnumNamesAlias) ||
-                ((OpenApiArray)schema.Extensions[xEnumNamesAlias]).Count != schema.Enum.Count)
+                ((OpenApiArray)schema.Extensions[xEnumNamesAlias]).Count != enumElements.Length)
             {
                 return null;
             }
 
             var sb = new StringBuilder();
-            for (var i = 0; i < schema.Enum.Count; i++)
+            for (var i = 0; i < enumElements.Length; i++)
             {
-                if (schema.Enum[i] is OpenApiInteger schemaEnumInt)
+                if (enumElements[i] is OpenApiInteger schemaEnumInt)
                 {
                     var value = schemaEnumInt.Value;
                     var name = ((OpenApiString)((OpenApiArray)schema.Extensions[xEnumNamesAlias])[i]).Value;
                     sb.Append($"{newLine}{newLine}{value} = {name}");
                 }
-                else if (schema.Enum[i] is OpenApiString schemaEnumString)
+                else if (enumElements[i] is OpenApiString schemaEnumString)
                 {
                     var value = schemaEnumString.Value;
                     sb.Append($"{newLine}{newLine}{value}");
@@ -241,7 +243,7 @@ internal static string AddEnumValuesDescription(
                     }
 
                     var xEnumDescriptions = (OpenApiArray)schema.Extensions[xEnumDescriptionsAlias];
-                    if (xEnumDescriptions?.Count == schema.Enum.Count)
+                    if (xEnumDescriptions?.Count == enumElements.Length)
                     {
                         var description = ((OpenApiString)((OpenApiArray)schema.Extensions[xEnumDescriptionsAlias])[i]).Value;
                         if (!string.IsNullOrWhiteSpace(description))
diff --git a/src/Unchase.Swashbuckle.AspNetCore.Extensions/Filters/XEnumNamesParameterFilter.cs b/src/Unchase.Swashbuckle.AspNetCore.Extensions/Filters/XEnumNamesParameterFilter.cs
index 866f06d..77c5f98 100644
--- a/src/Unchase.Swashbuckle.AspNetCore.Extensions/Filters/XEnumNamesParameterFilter.cs
+++ b/src/Unchase.Swashbuckle.AspNetCore.Extensions/Filters/XEnumNamesParameterFilter.cs
@@ -86,6 +86,9 @@ public void Apply(
                 return;
             }
 
+            var nullableUnderlyingType = Nullable.GetUnderlyingType(typeInfo);
+            typeInfo = nullableUnderlyingType?.IsEnum == true ? nullableUnderlyingType : typeInfo;
+
             var enumsArray = new OpenApiArray();
             var enumsDescriptionsArray = new OpenApiArray();
             if (typeInfo.IsEnum)
diff --git a/src/Unchase.Swashbuckle.AspNetCore.Extensions/Filters/XEnumNamesSchemaFilter.cs b/src/Unchase.Swashbuckle.AspNetCore.Extensions/Filters/XEnumNamesSchemaFilter.cs
index bab25a2..3ec79d5 100644
--- a/src/Unchase.Swashbuckle.AspNetCore.Extensions/Filters/XEnumNamesSchemaFilter.cs
+++ b/src/Unchase.Swashbuckle.AspNetCore.Extensions/Filters/XEnumNamesSchemaFilter.cs
@@ -78,14 +78,17 @@ public void Apply(
                 return;
             }
 
-            var typeInfo = context.Type.GetTypeInfo();
+            var nullableUnderlyingType = Nullable.GetUnderlyingType(context.Type);
+            var enumType = nullableUnderlyingType?.IsEnum == true ? nullableUnderlyingType : context.Type;
+
+            var typeInfo = enumType.GetTypeInfo();
             var enumsArray = new OpenApiArray();
             var enumsDescriptionsArray = new OpenApiArray();
             if (typeInfo.IsEnum)
             {
                 var names = Enum
-                    .GetNames(context.Type)
-                    .Select(name => (Enum.Parse(context.Type, name), new OpenApiString(name)))
+                    .GetNames(enumType)
+                    .Select(name => (Enum.Parse(enumType, name), new OpenApiString(name)))
                     .GroupBy(x => x.Item1)
                     .Select(x => x.LastOrDefault().Item2)
                     .ToList();
@@ -98,7 +101,7 @@ public void Apply(
                 if (_includeXEnumDescriptions)
                 {
                     enumsDescriptionsArray.AddRange(EnumTypeExtensions
-                        .GetEnumValuesDescription(context.Type, _descriptionSources, _xmlNavigators, _includeXEnumRemarks)
+                        .GetEnumValuesDescription(enumType, _descriptionSources, _xmlNavigators, _includeXEnumRemarks)
                         .GroupBy(x => x.EnumValue)
                         .Select(x => x.LastOrDefault().EnumDescription));
                     if (!schema.Extensions.ContainsKey(_xEnumDescriptionsAlias) && enumsDescriptionsArray.Any())