diff --git a/src/plugin/callback_ext.rs b/src/plugin/callback_ext.rs
index ff78ca7ff..8312fffd4 100644
--- a/src/plugin/callback_ext.rs
+++ b/src/plugin/callback_ext.rs
@@ -28,7 +28,7 @@ pub(super) fn ext_support_callback(
                 if crate::server::plugin_block_input(peer, block) == block {
                     null()
                 } else {
-                    make_return_code_msg(errno::ERR_CALLBACK_FAILED, "Failed to block input")
+                    make_return_code_msg(errno::ERR_CALLBACK_FAILED, "")
                 }
             } else {
                 make_return_code_msg(
diff --git a/src/plugin/callback_msg.rs b/src/plugin/callback_msg.rs
index 39abca67a..db0191376 100644
--- a/src/plugin/callback_msg.rs
+++ b/src/plugin/callback_msg.rs
@@ -79,7 +79,7 @@ macro_rules! early_return_value {
         match $e {
             Err(e) => return make_return_code_msg(
                 errno::$code,
-                &format!("Failed to {} '{:?}'", format_args!($($arg)*), e),
+                &format!("Failed to {} '{}'", format_args!($($arg)*), e),
             ),
             Ok(v) => v,
         }