diff --git a/serde/src/de/mod.rs b/serde/src/de/mod.rs
index a574a1ce..7113ab2c 100644
--- a/serde/src/de/mod.rs
+++ b/serde/src/de/mod.rs
@@ -1019,6 +1019,7 @@ pub trait Deserializer<'de>: Sized {
     ///
     /// NOTE: Implementing this method and returning `false` is considered a breaking
     /// change as it may alter how any given type tries to deserialize itself.
+    #[inline]
     fn is_human_readable(&self) -> bool { true }
 }
 
diff --git a/serde/src/ser/mod.rs b/serde/src/ser/mod.rs
index 8ba8fa2b..ee32428f 100644
--- a/serde/src/ser/mod.rs
+++ b/serde/src/ser/mod.rs
@@ -1371,6 +1371,7 @@ pub trait Serializer: Sized {
     ///
     /// NOTE: Implementing this method and returning `false` is considered a breaking
     /// change as it may alter how any given type tries to serialize itself.
+    #[inline]
     fn is_human_readable(&self) -> bool { true }
 }