diff --git a/src/boxed.rs b/src/boxed.rs
index 74730960..1a38b560 100644
--- a/src/boxed.rs
+++ b/src/boxed.rs
@@ -366,10 +366,10 @@ impl<T: 'static, MM: BoxedMemoryManager<T>> Uninitialized for Boxed<T, MM> {
     unsafe fn uninitialized() -> Self {
         Boxed {
             inner: {
-                let mut inner = Box::<T>::new(mem::MaybeUninit::zeroed().assume_init());
-                MM::init(&mut *inner);
+                let mut inner = Box::new(mem::MaybeUninit::zeroed());
+                MM::init(inner.as_mut_ptr());
 
-                AnyBox::Native(inner)
+                AnyBox::Native(Box::new(inner.assume_init()))
             },
             _dummy: PhantomData,
         }
diff --git a/src/object.rs b/src/object.rs
index c7ce0195..9c3216e0 100644
--- a/src/object.rs
+++ b/src/object.rs
@@ -1438,12 +1438,13 @@ impl<T: ObjectType> ObjectExt for T {
 
     fn downgrade(&self) -> WeakRef<T> {
         unsafe {
-            let w = WeakRef(Box::new(mem::MaybeUninit::zeroed().assume_init()), PhantomData);
+            let mut w = Box::new(mem::MaybeUninit::zeroed());
             gobject_sys::g_weak_ref_init(
-                mut_override(&*w.0),
+                mut_override((&mut *w).as_mut_ptr()),
                 self.as_object_ref().to_glib_none().0,
             );
-            w
+
+            WeakRef(Box::new((&mut *w).assume_init()), PhantomData)
         }
     }
 
@@ -1532,9 +1533,13 @@ pub struct WeakRef<T: ObjectType>(Box<gobject_sys::GWeakRef>, PhantomData<*const
 impl<T: ObjectType> WeakRef<T> {
     pub fn new() -> WeakRef<T> {
         unsafe {
-            let w = WeakRef(Box::new(mem::MaybeUninit::zeroed().assume_init()), PhantomData);
-            gobject_sys::g_weak_ref_init(mut_override(&*w.0), ptr::null_mut());
-            w
+            let mut w = Box::new(mem::MaybeUninit::zeroed());
+            gobject_sys::g_weak_ref_init(
+                (&mut *w).as_mut_ptr(),
+                ptr::null_mut(),
+            );
+
+            WeakRef(Box::new((&mut *w).assume_init()), PhantomData)
         }
     }
 
diff --git a/src/time_val.rs b/src/time_val.rs
index 0132b1d7..32bcc4a9 100644
--- a/src/time_val.rs
+++ b/src/time_val.rs
@@ -27,6 +27,6 @@ impl<'a> ToGlibPtrMut<'a, *mut glib_sys::GTimeVal> for TimeVal {
 
 impl Uninitialized for TimeVal {
     unsafe fn uninitialized() -> TimeVal {
-        mem::MaybeUninit::zeroed().assume_init()
+        mem::zeroed()
     }
 }
diff --git a/src/value.rs b/src/value.rs
index 3f054c1c..e552726f 100644
--- a/src/value.rs
+++ b/src/value.rs
@@ -199,7 +199,7 @@ impl Value {
     }
 
     #[doc(hidden)]
-    pub fn into_raw(mut self) -> gobject_sys::GValue {
+    pub fn into_raw(self) -> gobject_sys::GValue {
         unsafe {
             let ret = ptr::read(&self.0);
             mem::forget(self);
@@ -273,7 +273,7 @@ impl From<SendValue> for Value {
 
 impl Uninitialized for Value {
     unsafe fn uninitialized() -> Value {
-        Value(mem::MaybeUninit::zeroed().assume_init(), PhantomData)
+        mem::zeroed()
     }
 }