diff --git a/source/docs/dict/update.rst b/source/docs/dict/update.rst
index a2ffe7d..798cd1f 100644
--- a/source/docs/dict/update.rst
+++ b/source/docs/dict/update.rst
@@ -19,7 +19,7 @@ Return Value
 
 Time Complexity
 ===============
-#TODO
+$O(N)$ - linear time
 
 Example 1
 =========