diff --git a/include/curl_wrapper.hpp b/include/curl_wrapper.hpp
index c5e807f..0088197 100644
--- a/include/curl_wrapper.hpp
+++ b/include/curl_wrapper.hpp
@@ -222,7 +222,7 @@ protected:
      *
      *  @since  0.1.0
      */
-    void set_proxy(string_view proxy);
+    virtual void set_proxy(string_view proxy);
 
     /*!
      *  @brief  Set OAuth 2.0 Bearer Access Token.
@@ -237,14 +237,14 @@ protected:
      *
      *  @since  0.3.0
      */
-    void set_cainfo(string_view path);
+    virtual void set_cainfo(string_view path);
 
     /*!
      *  @brief  Sets the User-Agent.
      *
      *  @since  0.3.0
      */
-    void set_useragent(string_view useragent);
+    virtual void set_useragent(string_view useragent);
 
 private:
     CURL *_connection;
diff --git a/include/instance.hpp b/include/instance.hpp
index ca1cfe5..225f106 100644
--- a/include/instance.hpp
+++ b/include/instance.hpp
@@ -148,7 +148,7 @@ public:
      *  Sets also the proxy for all Connection%s that are initialized with this
      *  Instance afterwards.
      */
-    void set_proxy(const string_view proxy)
+    void set_proxy(const string_view proxy) override
     {
         _proxy = proxy;
         CURLWrapper::set_proxy(proxy);
@@ -187,7 +187,7 @@ public:
      *
      *  @since  0.3.0
      */
-    void set_cainfo(string_view path)
+    void set_cainfo(string_view path) override
     {
         _cainfo = path;
         CURLWrapper::set_cainfo(path);
@@ -201,7 +201,7 @@ public:
      *
      *  @since  0.3.0
      */
-    void set_useragent(const string_view useragent)
+    void set_useragent(const string_view useragent) override
     {
         _useragent = useragent;
         CURLWrapper::set_useragent(useragent);