diff --git a/src/Atc.OpenApi/Extensions/OpenApiSchemaExtensions.cs b/src/Atc.OpenApi/Extensions/OpenApiSchemaExtensions.cs
index 6943dd20..4d2a2e22 100644
--- a/src/Atc.OpenApi/Extensions/OpenApiSchemaExtensions.cs
+++ b/src/Atc.OpenApi/Extensions/OpenApiSchemaExtensions.cs
@@ -780,9 +780,13 @@ public static string GetModelName(this OpenApiSchema schema, bool ensureFirstCha
 
         if (ensureFirstCharacterToUpper)
         {
-            return schema.Items is null
-                ? schema.Reference.Id.EnsureFirstCharacterToUpper()
-                : schema.Items.Reference.Id.EnsureFirstCharacterToUpper();
+            var dataType = schema.Items is null
+                ? schema.Reference.Id
+                : schema.Items.Reference.Id;
+
+            return string.Equals(dataType, OpenApiDataTypeConstants.String, StringComparison.Ordinal)
+                ? dataType
+                : dataType.PascalCase(ModelNameSeparators, removeSeparators: true);
         }
 
         return schema.Items is null
diff --git a/test/Atc.OpenApi.Tests/XUnitTestData/TestMemberDataForOpenApiSchemaExtensions.cs b/test/Atc.OpenApi.Tests/XUnitTestData/TestMemberDataForOpenApiSchemaExtensions.cs
index 78fb9368..2c51d57c 100644
--- a/test/Atc.OpenApi.Tests/XUnitTestData/TestMemberDataForOpenApiSchemaExtensions.cs
+++ b/test/Atc.OpenApi.Tests/XUnitTestData/TestMemberDataForOpenApiSchemaExtensions.cs
@@ -1287,6 +1287,11 @@ public static TheoryData<string, OpenApiSchema> GetModelNameItemData
             { "Pet", TestDataOpenApiFactory.CreateSchemaPet() },
             { string.Empty,  TestDataOpenApiSchemaOfTypeFactory.CreateString() },
             { string.Empty,  TestDataOpenApiSchemaOfTypeFactory.CreateListString() },
+            { "HalloWorld",  TestDataOpenApiFactory.CreateSchemaWithModelName("Hallo World") },
+            { "HalloWorld",  TestDataOpenApiFactory.CreateSchemaWithModelName("Hallo_World_") },
+            { "HalloWorld",  TestDataOpenApiFactory.CreateSchemaWithModelName("Hallo.World_") },
+            { "HalloWorld",  TestDataOpenApiFactory.CreateSchemaWithModelName("HalloWorld_") },
+            { "HalloWorld",  TestDataOpenApiFactory.CreateSchemaWithModelName("HalloWorld.") },
         };
 
     public static TheoryData<string, OpenApiSchema, bool> GetModelNameEnsureFirstCharacterToUpperItemData