diff --git a/serde/src/de/impls.rs b/serde/src/de/impls.rs
index 76dccf7f..d4591690 100644
--- a/serde/src/de/impls.rs
+++ b/serde/src/de/impls.rs
@@ -646,7 +646,6 @@ array_impls! {
 ///////////////////////////////////////////////////////////////////////////////
 
 macro_rules! tuple_impls {
-    () => {};
     ($($len:expr => $visitor:ident => ($($name:ident),+),)+) => {
         $(
             /// Construct a tuple visitor.