diff --git a/README.md b/README.md
index f90e13f..342f90f 100644
--- a/README.md
+++ b/README.md
@@ -763,7 +763,7 @@ Two caveats to mention to this approach:
 
 1. There might be cases where you actually want to modify the input object, but when you adopt this programming practice you will find that those cases are pretty rare. Most things can be refactored to have no side effects! (see [pure function](https://en.wikipedia.org/wiki/Pure_function))
 
-2. Cloning big objects can be very expensive in terms of performance. Luckily, this isn't a big issue in practice because there are [great libraries](https://facebook.github.io/immutable-js/) that allow this kind of programming approach to be fast and not as memory intensive as it would be for you to manually clone objects and arrays.
+2. Cloning big objects can be very expensive in terms of performance. Luckily, this isn't a big issue in practice because there are [great libraries](https://github.com/immutable-js/immutable-js) that allow this kind of programming approach to be fast and not as memory intensive as it would be for you to manually clone objects and arrays.
 
 **Bad:**