diff --git a/src/lib.rs b/src/lib.rs
index 05e9ded..b72f76c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -116,13 +116,13 @@ use alloc::vec;
 use core::iter::FromIterator;
 
 #[cfg(not(feature = "std"))]
-use core::{fmt, mem, ops, slice};
+use core::{fmt, hint, mem, ops, slice};
 
 #[cfg(feature = "std")]
 use std::iter::FromIterator;
 
 #[cfg(feature = "std")]
-use std::{fmt, mem, ops, slice, vec};
+use std::{fmt, hint, mem, ops, slice, vec};
 
 /// Pre-allocated storage for a uniform data type
 ///
@@ -732,9 +732,12 @@ impl<T> Slab<T> {
     }
 
     /// Return a reference to the value associated with the given key without
-    /// performing bounds checking.
+    /// without checking that there is an element associated with that key.
     ///
-    /// This function should be used with care.
+    /// # Safety
+    ///
+    /// * The key must be within bounds
+    /// * There must be a value present at the slot the key refers to
     ///
     /// # Examples
     ///
@@ -750,14 +753,17 @@ impl<T> Slab<T> {
     pub unsafe fn get_unchecked(&self, key: usize) -> &T {
         match *self.entries.get_unchecked(key) {
             Entry::Occupied(ref val) => val,
-            _ => unreachable!(),
+            _ => hint::unreachable_unchecked(),
         }
     }
 
     /// Return a mutable reference to the value associated with the given key
-    /// without performing bounds checking.
+    /// without checking that there is an element associated with that key.
     ///
-    /// This function should be used with care.
+    /// # Safety
+    ///
+    /// * The key must be within bounds
+    /// * There must be a value present at the slot the key refers to
     ///
     /// # Examples
     ///
@@ -776,7 +782,7 @@ impl<T> Slab<T> {
     pub unsafe fn get_unchecked_mut(&mut self, key: usize) -> &mut T {
         match *self.entries.get_unchecked_mut(key) {
             Entry::Occupied(ref mut val) => val,
-            _ => unreachable!(),
+            _ => hint::unreachable_unchecked(),
         }
     }