diff --git a/serde/src/ser/mod.rs b/serde/src/ser/mod.rs
index 3cc87d4e..02c43657 100644
--- a/serde/src/ser/mod.rs
+++ b/serde/src/ser/mod.rs
@@ -643,7 +643,7 @@ pub trait Serializer: Sized {
     {
         // TODO https://github.com/serde-rs/serde/issues/805
         // Remove this impl and force no_std formats to implement collect_str.
-        Err(Error::custom("Default impl of collect_str errors out for no_std builds"))
+        Err(Error::custom("this no_std format does not support serializing strings with collect_str"))
     }
 }