diff --git a/src/posix/platform/mainloop.hpp b/src/posix/platform/mainloop.hpp
index d4f6ac8ff..4f0fa7cc9 100644
--- a/src/posix/platform/mainloop.hpp
+++ b/src/posix/platform/mainloop.hpp
@@ -65,6 +65,12 @@ public:
      */
     virtual void Process(const otSysMainloopContext &aContext) = 0;
 
+    /**
+     * This method marks desturctor virtual method.
+     *
+     */
+    virtual ~Source() = default;
+
 private:
     Source *mNext = nullptr;
 };