diff --git a/frontends/library/stainless/lang/Set.scala b/frontends/library/stainless/lang/Set.scala
index a299eecf7..8da2ba422 100644
--- a/frontends/library/stainless/lang/Set.scala
+++ b/frontends/library/stainless/lang/Set.scala
@@ -36,6 +36,11 @@ object Set {
       new Set(set.theSet.map(f))
     }
 
+    @extern @pure
+    def flatMap[B](f: A => Set[B]): Set[B] = {
+      new Set(set.theSet.flatMap(f(_).theSet))
+    }
+
     @extern @pure
     def mapPost1[B](f: A => B)(a: A): Unit = {
       ()
diff --git a/inox b/inox
index 516bf217f..6062f8f95 160000
--- a/inox
+++ b/inox
@@ -1 +1 @@
-Subproject commit 516bf217f053996f73a13ce1b400af4551437e12
+Subproject commit 6062f8f9552e5f71d441d7d0365bcb17e67fc224