diff --git a/library/core/src/slice/iter.rs b/library/core/src/slice/iter.rs
index 730009568dd3..90afd00f21db 100644
--- a/library/core/src/slice/iter.rs
+++ b/library/core/src/slice/iter.rs
@@ -3018,6 +3018,11 @@ where P: FnMut(&T, &T) -> bool,
             (1, Some(self.slice.len()))
         }
     }
+
+    #[inline]
+    fn last(self) -> Option<Self::Item> {
+        self.next_back()
+    }
 }
 
 #[unstable(feature = "slice_group_by", issue = "0")]
@@ -3098,6 +3103,11 @@ where P: FnMut(&T, &T) -> bool,
             (1, Some(self.slice.len()))
         }
     }
+
+    #[inline]
+    fn last(self) -> Option<Self::Item> {
+        self.next_back()
+    }
 }
 
 #[unstable(feature = "slice_group_by", issue = "0")]