diff --git a/src/main/java/io/reactivex/functions/Function.java b/src/main/java/io/reactivex/functions/Function.java
index 2aece7dc1b..7c6d095314 100644
--- a/src/main/java/io/reactivex/functions/Function.java
+++ b/src/main/java/io/reactivex/functions/Function.java
@@ -29,6 +29,5 @@ public interface Function<T, R> {
      * @return the output value
      * @throws Exception on error
      */
-    @NonNull
     R apply(@NonNull T t) throws Exception;
 }