diff --git a/src/de.rs b/src/de.rs
index 7eba7f48a..b4c5ef7dc 100644
--- a/src/de.rs
+++ b/src/de.rs
@@ -93,7 +93,9 @@ impl<'a> Deserializer<read::StrRead<'a>> {
 
 macro_rules! overflow {
     ($a:ident * 10 + $b:ident, $c:expr) => {
-        $a >= $c / 10 && ($a > $c / 10 || $b > $c % 10)
+        match $c {
+            c => $a >= c / 10 && ($a > c / 10 || $b > c % 10),
+        }
     };
 }