diff --git a/SharedPtr.hpp b/SharedPtr.hpp
index 6f3de5b..0735f20 100644
--- a/SharedPtr.hpp
+++ b/SharedPtr.hpp
@@ -16,7 +16,7 @@ template <typename T> struct Base {
 
   T *ptr;
   Base(T *ptr) : ptr{ptr} {}
-  template <typename U> Base(Base<U> const &ptr) : ptr{ptr.ptr} {}
+  template <typename U> Base(Base<U> &ptr) : ptr{ptr.ptr} {}
 
 public:
   virtual T &operator*() { return *ptr; }
@@ -28,6 +28,7 @@ template <typename T, typename U> class MyDerived : public Base<T> {
 
 public:
   MyDerived(U *ptr) : Base<T>{ptr} { this->ptr = ptr; }
+  MyDerived(Base<U> &ptr) : Base<T>{ptr.ptr} { this->ptr = ptr.ptr; }
   U &operator*() { return *ptr; }
   U *operator->() { return ptr; }
   virtual ~MyDerived() { delete this->ptr; }
@@ -46,7 +47,9 @@ public:
             static_cast<std::size_t>(ptr ? 1 : 0)}} {}
   SharedPtr(const SharedPtr &p) : ptr{p.ptr}, count{p.count} {}
   template <typename U>
-  SharedPtr(const SharedPtr<U> &p) : ptr(p.ptr), count{p.count} {
+  SharedPtr(const SharedPtr<U> &p)
+      : ptr(MyDerived<U, T>(const_cast<cs440::Base<U> &>(*p.ptr))),
+        count{p.count} {
     (*count)++;
   }
   SharedPtr(SharedPtr &&p) : ptr{p.ptr} { p.ptr = nullptr; }