diff --git a/include/oneapi/dpl/pstl/iterator_impl.h b/include/oneapi/dpl/pstl/iterator_impl.h
index 6863e3c1380..929eec7c773 100644
--- a/include/oneapi/dpl/pstl/iterator_impl.h
+++ b/include/oneapi/dpl/pstl/iterator_impl.h
@@ -516,14 +516,14 @@ class transform_iterator
     {
         __my_it_ = __input.__my_it_;
 
-        // If copy assignment is available, copy the functor, otherwise skip it.
-        // For non-copy assignable functors, this copy assignment operator departs from the sycl 2020 specification
-        // requirement of device copyable types for copy assignment to be the same as a bitwise copy of the object.
-        // TODO: Explore (ABI breaking) change to use std::optional or similar and using copy constructor to implement
-        //       copy assignment to better comply with SYCL 2020 specification.
-        if constexpr (std::is_copy_assignable_v<_UnaryFunc>)
+        // Implement functor copy assignment via destroy + copy-construct rather than _UnaryFunc::operator=.
+        // This supports copy assignment of functors which are not copy assignable (like c++17 lambdas).
+        // For a unary functor who's copy assignment operator differs from its copy constructor, the semantics of this
+        // copy assignment will follow that of its copy constructor.
+        if (this != std::addressof(__input))
         {
-            __my_unary_func_ = __input.__my_unary_func_;
+            __my_unary_func_.~_UnaryFunc();
+            ::new (std::addressof(__my_unary_func_)) _UnaryFunc(__input.__my_unary_func_);
         }
         return *this;
     }
diff --git a/test/parallel_api/iterator/transform_iterator_constructible.pass.cpp b/test/parallel_api/iterator/transform_iterator_constructible.pass.cpp
index 589b5b2fe20..215214a7f48 100644
--- a/test/parallel_api/iterator/transform_iterator_constructible.pass.cpp
+++ b/test/parallel_api/iterator/transform_iterator_constructible.pass.cpp
@@ -101,11 +101,11 @@ test_copy_assignment()
 
     EXPECT_EQ(9, trans6[5], "transform_iterator returns the incorrect result");
 
-    //should NOT copy __x state of functor (but still allows assignment of iterator)
+    //should still copy __x state of functor (despite not being copy-assignable)
     trans6 = trans5;
 
     //trans6 functor.__x remains the same, but iterator has been updated to be 100 elements later in the counting iter
-    EXPECT_EQ(109, trans6[5], "transform_iterator assignment with non-copy-assignable functor copies functor");
+    EXPECT_EQ(108, trans6[5], "transform_iterator assignment with non-copy-assignable functor still copies functor");
 }
 
 void