diff --git a/jdk/src/java.base/share/classes/java/util/stream/Stream.java b/jdk/src/java.base/share/classes/java/util/stream/Stream.java
index 1ec21ed2b57..225664042a6 100644
--- a/jdk/src/java.base/share/classes/java/util/stream/Stream.java
+++ b/jdk/src/java.base/share/classes/java/util/stream/Stream.java
@@ -1327,7 +1327,7 @@ public interface Stream<T> extends BaseStream<T, Stream<T>> {
      * @param s the {@code Supplier} of generated elements
      * @return a new infinite sequential unordered {@code Stream}
      */
-    public static<T> Stream<T> generate(Supplier<T> s) {
+    public static<T> Stream<T> generate(Supplier<? extends T> s) {
         Objects.requireNonNull(s);
         return StreamSupport.stream(
                 new StreamSpliterators.InfiniteSupplyingSpliterator.OfRef<>(Long.MAX_VALUE, s), false);
diff --git a/jdk/src/java.base/share/classes/java/util/stream/StreamSpliterators.java b/jdk/src/java.base/share/classes/java/util/stream/StreamSpliterators.java
index 8236255d5ef..4606ce30306 100644
--- a/jdk/src/java.base/share/classes/java/util/stream/StreamSpliterators.java
+++ b/jdk/src/java.base/share/classes/java/util/stream/StreamSpliterators.java
@@ -1346,9 +1346,9 @@ class StreamSpliterators {
         }
 
         static final class OfRef<T> extends InfiniteSupplyingSpliterator<T> {
-            final Supplier<T> s;
+            final Supplier<? extends T> s;
 
-            OfRef(long size, Supplier<T> s) {
+            OfRef(long size, Supplier<? extends T> s) {
                 super(size);
                 this.s = s;
             }