diff --git a/CHANGELOG.next.toml b/CHANGELOG.next.toml
index e7157b365edba541782aa46370986d9ccb11c977..aec1605b3757bb49371a9c35154c2a2452f5a3a1 100644
--- a/CHANGELOG.next.toml
+++ b/CHANGELOG.next.toml
@@ -11,6 +11,12 @@
 # meta = { "breaking" = false, "tada" = false, "bug" = false, "target" = "client | server | all"}
 # author = "rcoh"
 
+[[smithy-rs]]
+message = "Avoid intermediate vec allocations in AggregatedBytes::to_vec."
+author = "yotamofek"
+references = ["smithy-rs#2786"]
+meta = { "breaking" = false, "tada" = false, "bug" = false }
+
 [[smithy-rs]]
 message = "Fix bug in AWS JSON 1.x routers where, if a service had more than 14 operations, the router was created without the route for the 15th operation."
 author = "thor-bjorgvinsson"
diff --git a/rust-runtime/aws-smithy-http/src/byte_stream.rs b/rust-runtime/aws-smithy-http/src/byte_stream.rs
index fcd697c7b4fc2fc1f8633bb535c1d72c2cf6d319..e067018a9db01b3a7a5bf747c1b82b1b84fc7358 100644
--- a/rust-runtime/aws-smithy-http/src/byte_stream.rs
+++ b/rust-runtime/aws-smithy-http/src/byte_stream.rs
@@ -484,11 +484,7 @@ impl AggregatedBytes {
 
     /// Convert this buffer into a `Vec<u8>`
     pub fn to_vec(self) -> Vec<u8> {
-        self.0
-            .into_inner()
-            .into_iter()
-            .flat_map(|b| b.to_vec())
-            .collect()
+        self.0.into_inner().into_iter().flatten().collect()
     }
 }