diff --git a/crates/fj-core/src/services/service.rs b/crates/fj-core/src/services/service.rs
index 93b0cc20e..8069898c5 100644
--- a/crates/fj-core/src/services/service.rs
+++ b/crates/fj-core/src/services/service.rs
@@ -1,4 +1,4 @@
-use std::ops::{Deref, DerefMut};
+use std::ops::Deref;
 
 /// A service that controls access to some state
 ///
@@ -63,7 +63,7 @@ impl<S: State> Deref for Service<S> {
 }
 
 #[cfg(test)]
-impl<S: State> DerefMut for Service<S> {
+impl<S: State> std::ops::DerefMut for Service<S> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         &mut self.state
     }