diff --git a/plume-models/src/blogs.rs b/plume-models/src/blogs.rs
index 489589a1..0458895c 100644
--- a/plume-models/src/blogs.rs
+++ b/plume-models/src/blogs.rs
@@ -381,6 +381,7 @@ impl FromId<DbConn> for Blog {
                 .ok_or(Error::MissingApProperty)?
                 .to_string();
             if name.contains(&['<', '>', '&', '@', '\'', '"', ' ', '\t'][..]) {
+                tracing::error!("preferredUsername includes invalid character(s): {}", &name);
                 return Err(Error::InvalidValue);
             }
             (
diff --git a/plume-models/src/users.rs b/plume-models/src/users.rs
index 3908739c..8dbd2712 100644
--- a/plume-models/src/users.rs
+++ b/plume-models/src/users.rs
@@ -937,6 +937,7 @@ impl FromId<DbConn> for User {
             .to_string();
 
         if username.contains(&['<', '>', '&', '@', '\'', '"', ' ', '\t'][..]) {
+            tracing::error!("preferredUsername includes invalid character(s): {}", &username);
             return Err(Error::InvalidValue);
         }