diff --git a/src/test/java/org/opentripplanner/framework/collection/ListUtilsTest.java b/src/test/java/org/opentripplanner/framework/collection/ListUtilsTest.java
index 6e72d5626c5..33dce1f5574 100644
--- a/src/test/java/org/opentripplanner/framework/collection/ListUtilsTest.java
+++ b/src/test/java/org/opentripplanner/framework/collection/ListUtilsTest.java
@@ -56,5 +56,11 @@ void distinctByKey() {
     assertEquals(List.of(first, third), deduplicated);
   }
 
+  @Test
+  void ofNullable() {
+    assertEquals(List.of(), ListUtils.ofNullable(null));
+    assertEquals(List.of("A"), ListUtils.ofNullable("A"));
+  }
+
   private record Wrapper(int i, String string) {}
 }