diff --git a/serde/src/private/de.rs b/serde/src/private/de.rs
index 1396b103..7f597ede 100644
--- a/serde/src/private/de.rs
+++ b/serde/src/private/de.rs
@@ -2758,7 +2758,7 @@ where
     where
         V: Visitor<'de>,
     {
-        for entry in self.0.iter_mut() {
+        for entry in self.0 {
             if let Some((key, value)) = flat_map_take_entry(entry, variants) {
                 return visitor.visit_enum(EnumDeserializer::new(key, Some(value)));
             }
diff --git a/serde_derive/src/bound.rs b/serde_derive/src/bound.rs
index 7bdb046e..a38e7c2b 100644
--- a/serde_derive/src/bound.rs
+++ b/serde_derive/src/bound.rs
@@ -259,7 +259,7 @@ pub fn with_bound(
     };
     match &cont.data {
         Data::Enum(variants) => {
-            for variant in variants.iter() {
+            for variant in variants {
                 let relevant_fields = variant
                     .fields
                     .iter()
diff --git a/serde_derive/src/internals/check.rs b/serde_derive/src/internals/check.rs
index 28c97bc6..4a7f52c6 100644
--- a/serde_derive/src/internals/check.rs
+++ b/serde_derive/src/internals/check.rs
@@ -195,7 +195,7 @@ fn check_variant_skip_attrs(cx: &Ctxt, cont: &Container) {
         Data::Struct(_, _) => return,
     };
 
-    for variant in variants.iter() {
+    for variant in variants {
         if variant.attrs.serialize_with().is_some() {
             if variant.attrs.skip_serializing() {
                 cx.error_spanned_by(