diff --git a/src/cached.rs b/src/cached.rs
index b9b0ba2..0cea7c6 100644
--- a/src/cached.rs
+++ b/src/cached.rs
@@ -68,7 +68,7 @@ impl<T: Clone + Debug> Cached<T> {
     /// Moves the value from `Self::Used` to `Self::Unused`.
     pub fn set_unused(&mut self) {
         if matches!(*self, Self::Used(_)) {
-            *self = Self::Unused(self.take_used().unwrap());
+            *self = Self::Unused(self.take_used().expect("cached value should be used"));
         }
     }