diff --git a/Cargo.toml b/Cargo.toml
index 220f8b2..f77070f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "smallvec"
-version = "2.0.0-alpha.9"
+version = "2.0.0-alpha.10"
 edition = "2021"
 rust-version = "1.57"
 authors = ["The Servo Project Developers"]
diff --git a/src/lib.rs b/src/lib.rs
index 42c04c3..37c2123 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -500,6 +500,11 @@ pub struct IntoIter<T, const N: usize> {
     _marker: PhantomData<T>,
 }
 
+// SAFETY: IntoIter has unique ownership of its contents.  Sending (or sharing) an `IntoIter<T, N>`
+// is equivalent to sending (or sharing) a `SmallVec<T, N>`.
+unsafe impl<T, const N: usize> Send for IntoIter<T, N> where T: Send {}
+unsafe impl<T, const N: usize> Sync for IntoIter<T, N> where T: Sync {}
+
 impl<T, const N: usize> IntoIter<T, N> {
     #[inline]
     const fn is_zst() -> bool {
@@ -1502,11 +1507,11 @@ impl<T, const N: usize> SmallVec<T, N> {
         let mut iter = iter.fuse();
         let (lower_bound, _) = iter.size_hint();
         self.reserve(lower_bound);
-        let mut len = self.len();
         let mut capacity = self.capacity();
         let mut ptr = self.as_mut_ptr();
         unsafe {
             loop {
+                let mut len = self.len();
                 // SAFETY: ptr is valid for `capacity - len` writes
                 ptr = ptr.add(len);
                 let mut guard = DropGuard { ptr, len: 0 };
@@ -1520,7 +1525,6 @@ impl<T, const N: usize> SmallVec<T, N> {
                 // At this point we either consumed all capacity or the iterator is exhausted (fused)
                 if let Some(item) = iter.next() {
                     self.push(item);
-                    len += 1;
                 } else {
                     return;
                 }