diff --git a/tracing/mainmatter-workshop/README.md b/tracing/mainmatter-workshop/README.md
index aa4cadb..fb50b4a 100644
--- a/tracing/mainmatter-workshop/README.md
+++ b/tracing/mainmatter-workshop/README.md
@@ -13,7 +13,8 @@ As stated in the exercise brief, this example will:
   - Create a top-level INFO span for each incoming request;
   - Track the number of concurrent requests using a gauge;
   - Track request duration using a histogram;
-  - Track the number of handled requests All metrics should include success/failure as a label.
+  - Track the number of handled requests
+- All metrics should include success/failure as a label.
 
 ## Usage
 
diff --git a/tracing/mainmatter-workshop/src/middleware.rs b/tracing/mainmatter-workshop/src/middleware.rs
index bef2340..130ded8 100644
--- a/tracing/mainmatter-workshop/src/middleware.rs
+++ b/tracing/mainmatter-workshop/src/middleware.rs
@@ -31,8 +31,14 @@ pub(crate) async fn request_telemetry(
         );
     };
 
+    let outcome = if res.status().is_success() || res.status().is_redirection() {
+        "success"
+    } else {
+        "failure"
+    };
+
     let diff = now.elapsed();
-    metrics::histogram!(HISTOGRAM_HTTP_REQUEST_DURATION).record(diff);
+    metrics::histogram!(HISTOGRAM_HTTP_REQUEST_DURATION, "outcome" => outcome).record(diff);
 
     metrics::gauge!(GAUGE_HTTP_CONCURRENT_REQUESTS).decrement(1);