diff --git a/src/de.rs b/src/de.rs
index 5632b583..c1bfeb8b 100644
--- a/src/de.rs
+++ b/src/de.rs
@@ -663,6 +663,11 @@ where
         }
     }
 
+    #[inline]
+    fn is_human_readable(&self) -> bool {
+        false
+    }
+
     forward_to_deserialize_any! {
         bool i8 i16 i32 i64 u8 u16 u32 u64 f32 f64 char str string unit
         unit_struct seq tuple tuple_struct map struct identifier ignored_any
diff --git a/src/ser.rs b/src/ser.rs
index f0d524ee..5f20dbc3 100644
--- a/src/ser.rs
+++ b/src/ser.rs
@@ -454,6 +454,7 @@ where
         self.serialize_struct(name, len)
     }
 
+    #[inline]
     fn is_human_readable(&self) -> bool {
         false
     }