diff --git a/src/lib.rs b/src/lib.rs
index 01bd637..997b01c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,8 @@
 #![feature(const_fn)]
-#![cfg_attr(feature = "alloc_ref", feature(allocator_api, alloc_layout_extra))]
+#![cfg_attr(
+    feature = "alloc_ref",
+    feature(allocator_api, alloc_layout_extra, nonnull_slice_from_raw_parts)
+)]
 #![no_std]
 
 #[cfg(test)]
@@ -13,7 +16,7 @@ extern crate alloc;
 
 use alloc::alloc::Layout;
 #[cfg(feature = "alloc_ref")]
-use alloc::alloc::{AllocErr, AllocInit, AllocRef, MemoryBlock};
+use alloc::alloc::{AllocErr, AllocRef};
 #[cfg(feature = "use_spin")]
 use core::alloc::GlobalAlloc;
 use core::mem;
@@ -158,22 +161,12 @@ impl Heap {
 
 #[cfg(feature = "alloc_ref")]
 unsafe impl AllocRef for Heap {
-    fn alloc(&mut self, layout: Layout, init: AllocInit) -> Result<MemoryBlock, AllocErr> {
+    fn alloc(&mut self, layout: Layout) -> Result<NonNull<[u8]>, AllocErr> {
         if layout.size() == 0 {
-            return Ok(MemoryBlock {
-                ptr: layout.dangling(),
-                size: 0,
-            });
+            return Ok(NonNull::slice_from_raw_parts(layout.dangling(), 0));
         }
         match self.allocate_first_fit(layout) {
-            Ok(ptr) => {
-                let block = MemoryBlock {
-                    ptr,
-                    size: layout.size(),
-                };
-                unsafe { init.init(block) };
-                Ok(block)
-            }
+            Ok(ptr) => Ok(NonNull::slice_from_raw_parts(ptr, layout.size())),
             Err(()) => Err(AllocErr),
         }
     }