diff --git a/ctl/shared_ptr.h b/ctl/shared_ptr.h
index 2d4ff04f8..da112ff19 100644
--- a/ctl/shared_ptr.h
+++ b/ctl/shared_ptr.h
@@ -193,12 +193,15 @@ class shared_ptr
     {
     }
 
+    // TODO(mrdomino): blocked on ctl::ref
+#if 0
     template<typename U, typename D>
         requires is_convertible_v<U, T>
     shared_ptr(unique_ptr<U, D>&& r)
       : p(r.p), rc(__::shared_pointer<U, D>::make(r.release(), r.get_deleter()))
     {
     }
+#endif
 
     ~shared_ptr()
     {
diff --git a/test/ctl/shared_ptr_test.cc b/test/ctl/shared_ptr_test.cc
index 6ac7e10ea..359739ebe 100644
--- a/test/ctl/shared_ptr_test.cc
+++ b/test/ctl/shared_ptr_test.cc
@@ -155,6 +155,7 @@ main()
             return 9;
     }
 
+#if 0
     {
         g = 0;
         // You can create a shared_ptr from a unique_ptr.
@@ -166,6 +167,7 @@ main()
         if (g != 1)
             return 11;
     }
+#endif
 
     {
         g = 0;