diff --git a/serde_derive/src/de.rs b/serde_derive/src/de.rs
index 20ccb696..741baec7 100644
--- a/serde_derive/src/de.rs
+++ b/serde_derive/src/de.rs
@@ -1387,10 +1387,10 @@ fn deserialize_identifier(
     };
 
     let visit_index = if is_variant {
-        let variant_indices = 0u32..;
+        let variant_indices = 0u64..;
         let fallthrough_msg = format!("variant index 0 <= i < {}", fields.len());
         let visit_index = quote! {
-            fn visit_u32<__E>(self, __value: u32) -> _serde::export::Result<Self::Value, __E>
+            fn visit_u64<__E>(self, __value: u64) -> _serde::export::Result<Self::Value, __E>
                 where __E: _serde::de::Error
             {
                 match __value {
diff --git a/test_suite/tests/test_identifier.rs b/test_suite/tests/test_identifier.rs
index 76f1cffa..83a0d3b1 100644
--- a/test_suite/tests/test_identifier.rs
+++ b/test_suite/tests/test_identifier.rs
@@ -23,7 +23,10 @@ fn test_variant_identifier() {
         Bbb,
     }
 
+    assert_de_tokens(&V::Aaa, &[Token::U8(0)]);
+    assert_de_tokens(&V::Aaa, &[Token::U16(0)]);
     assert_de_tokens(&V::Aaa, &[Token::U32(0)]);
+    assert_de_tokens(&V::Aaa, &[Token::U64(0)]);
     assert_de_tokens(&V::Aaa, &[Token::Str("Aaa")]);
     assert_de_tokens(&V::Aaa, &[Token::Bytes(b"Aaa")]);
 }