diff --git a/src/DryGen.CSharpFromJsonSchema/CSharpFromJsonSchemaGenerator.cs b/src/DryGen.CSharpFromJsonSchema/CSharpFromJsonSchemaGenerator.cs
index 5def47c..803f44a 100644
--- a/src/DryGen.CSharpFromJsonSchema/CSharpFromJsonSchemaGenerator.cs
+++ b/src/DryGen.CSharpFromJsonSchema/CSharpFromJsonSchemaGenerator.cs
@@ -57,10 +57,7 @@ private static void RemoveSynteticSchemaProperty(JsonSchema jsonSchema)
     {
         // Hack to get rid of the syntetic $schema property we must use if we want additionalProperties = false in the topmost object
         const string schemaPropertyName = "$schema";
-        if (jsonSchema.Properties.ContainsKey(schemaPropertyName))
-        {
-            jsonSchema.Properties.Remove(schemaPropertyName);
-        }
+        jsonSchema.Properties.Remove(schemaPropertyName);
     }
 
     private static async Task<JsonSchema> LoadJsonSchemaFromFile(string? jsonSchemaFileName, JsonSchemaFileFormat jsonSchemaFileFormat)
diff --git a/src/DryGen.MermaidFromCSharp/ClassDiagram/ClassDiagramGenerator.cs b/src/DryGen.MermaidFromCSharp/ClassDiagram/ClassDiagramGenerator.cs
index 788d294..34aee9c 100644
--- a/src/DryGen.MermaidFromCSharp/ClassDiagram/ClassDiagramGenerator.cs
+++ b/src/DryGen.MermaidFromCSharp/ClassDiagram/ClassDiagramGenerator.cs
@@ -94,7 +94,7 @@ private static ClassDiagramClass[] ConvertExtensionMethodsToInstanceMethodsOnKno
         return classDiagramClasses.Except(removedExtensionClasses).ToArray();
     }
 
-    private static void GenerateClassAssociationsCompositionsAndAggregations(IDictionary<Type, ClassDiagramClass> classLookup, ClassDiagramClass classDiagramClass)
+    private static void GenerateClassAssociationsCompositionsAndAggregations(Dictionary<Type, ClassDiagramClass> classLookup, ClassDiagramClass classDiagramClass)
     {
         foreach (var property in classDiagramClass.Type.GetProperties(
             BindingFlags.Instance |
@@ -179,7 +179,7 @@ private static void GenerateClassInheritanceOrRealizationForInterfaces(Dictionar
         }
     }
 
-    private static void GenerateClassInheritanceForBaseType(IDictionary<Type, ClassDiagramClass> classLookup, ClassDiagramClass classDiagramClass)
+    private static void GenerateClassInheritanceForBaseType(Dictionary<Type, ClassDiagramClass> classLookup, ClassDiagramClass classDiagramClass)
     {
         if (classDiagramClass.Type.IsInterface)
         {