diff --git a/core/src/upgrade/select.rs b/core/src/upgrade/select.rs
index 1d5ab9abe53..c823d791cf7 100644
--- a/core/src/upgrade/select.rs
+++ b/core/src/upgrade/select.rs
@@ -25,6 +25,7 @@ use crate::{
 };
 use either::Either;
 use futures::future;
+use std::iter::{Chain, Map};
 
 /// Upgrade that combines two upgrades into one. Supports all the protocols supported by either
 /// sub-upgrade.
@@ -48,16 +49,24 @@ where
     B: UpgradeInfo,
 {
     type Info = EitherName<A::Info, B::Info>;
-    type InfoIter = InfoIterChain<
-        <A::InfoIter as IntoIterator>::IntoIter,
-        <B::InfoIter as IntoIterator>::IntoIter,
+    type InfoIter = Chain<
+        Map<<A::InfoIter as IntoIterator>::IntoIter, fn(A::Info) -> Self::Info>,
+        Map<<B::InfoIter as IntoIterator>::IntoIter, fn(B::Info) -> Self::Info>,
     >;
 
     fn protocol_info(&self) -> Self::InfoIter {
-        InfoIterChain(
-            self.0.protocol_info().into_iter(),
-            self.1.protocol_info().into_iter(),
-        )
+        let a = self
+            .0
+            .protocol_info()
+            .into_iter()
+            .map(EitherName::A as fn(A::Info) -> _);
+        let b = self
+            .1
+            .protocol_info()
+            .into_iter()
+            .map(EitherName::B as fn(B::Info) -> _);
+
+        a.chain(b)
     }
 }
 
@@ -94,32 +103,3 @@ where
         }
     }
 }
-
-/// Iterator that combines the protocol names of twp upgrades.
-#[derive(Debug, Clone)]
-pub struct InfoIterChain<A, B>(A, B);
-
-impl<A, B> Iterator for InfoIterChain<A, B>
-where
-    A: Iterator,
-    B: Iterator,
-{
-    type Item = EitherName<A::Item, B::Item>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if let Some(info) = self.0.next() {
-            return Some(EitherName::A(info));
-        }
-        if let Some(info) = self.1.next() {
-            return Some(EitherName::B(info));
-        }
-        None
-    }
-
-    fn size_hint(&self) -> (usize, Option<usize>) {
-        let (min1, max1) = self.0.size_hint();
-        let (min2, max2) = self.1.size_hint();
-        let max = max1.and_then(move |m1| max2.and_then(move |m2| m1.checked_add(m2)));
-        (min1.saturating_add(min2), max)
-    }
-}