diff --git a/src/map.rs b/src/map.rs
index eecd55a1..b346b77d 100644
--- a/src/map.rs
+++ b/src/map.rs
@@ -1031,6 +1031,18 @@ where
         }
     }
 
+    /// Return item index
+    pub fn entry_index<Q: ?Sized>(&self, key: &Q) -> Option<usize>
+    where
+        Q: Hash + Equivalent<K>,
+    {
+        if let Some((_, found)) = self.find(key) {
+            Some(found)
+        } else {
+            None
+        }
+    }
+
     pub fn get_mut<Q: ?Sized>(&mut self, key: &Q) -> Option<&mut V>
     where
         Q: Hash + Equivalent<K>,
diff --git a/src/set.rs b/src/set.rs
index 4b83f4b5..005e1ff5 100644
--- a/src/set.rs
+++ b/src/set.rs
@@ -327,6 +327,14 @@ where
         self.map.get_full(value).map(|(i, x, &())| (i, x))
     }
 
+    /// Return item index
+    pub fn entry_index<Q: ?Sized>(&self, value: &Q) -> Option<(usize)>
+    where
+        Q: Hash + Equivalent<T>,
+    {
+        self.map.entry_index(value)
+    }
+
     /// Adds a value to the set, replacing the existing value, if any, that is
     /// equal to the given one. Returns the replaced value.
     ///