diff --git a/exercises/bob/example.rs b/exercises/bob/example.rs
index a6512f867..60505ccc6 100644
--- a/exercises/bob/example.rs
+++ b/exercises/bob/example.rs
@@ -1,4 +1,4 @@
-pub fn reply(message: &str) -> &str {
+pub fn reply(message: &str) -> &'static str {
     if is_silence(message) { "Fine. Be that way!" }
     else if is_yelling(message) && is_question(message) { "Calm down, I know what I'm doing!" }
     else if is_yelling(message) { "Whoa, chill out!" }
diff --git a/exercises/bob/src/lib.rs b/exercises/bob/src/lib.rs
index d0417c9d1..cea08e1d6 100644
--- a/exercises/bob/src/lib.rs
+++ b/exercises/bob/src/lib.rs
@@ -1,3 +1,3 @@
-pub fn reply(message: &str) -> &str {
-    unimplemented!("have Bob reply to the incoming message: {}", message)
-}
+pub fn reply(message: &str) -> &'static str {
+    unimplemented!("have Bob reply to the incoming message: {}", message)
+}