diff --git a/lib/stdlib/src/lists.erl b/lib/stdlib/src/lists.erl
index 2c602fe56bac..dd1f9cbe02a7 100644
--- a/lib/stdlib/src/lists.erl
+++ b/lib/stdlib/src/lists.erl
@@ -2113,7 +2113,12 @@ flatmap(F, List) when is_function(F, 1) ->
     flatmap_1(F, List).
 
 flatmap_1(F, [Hd | Tail]) ->
-    F(Hd) ++ flatmap_1(F, Tail);
+    case F(Hd) of
+        % The two first clauses are an optimization
+        [] -> flatmap_1(F, Tail);
+        [Elem] -> [Elem | flatmap_1(F, Tail)];
+        List -> List ++ flatmap_1(F, Tail)
+    end;
 flatmap_1(_F, []) ->
     [].