diff --git a/java/com/google/gerrit/plugins/checks/api/CheckInput.java b/java/com/google/gerrit/plugins/checks/api/CheckInput.java
index 5d1d970..b337a79 100644
--- a/java/com/google/gerrit/plugins/checks/api/CheckInput.java
+++ b/java/com/google/gerrit/plugins/checks/api/CheckInput.java
@@ -22,9 +22,9 @@
 /** Input to create or update a {@link com.google.gerrit.plugins.checks.Check}. */
 public class CheckInput {
   /** UUID of the checker. */
-  public String checkerUuid;
+  @Nullable public String checkerUuid;
   /** State of the check. */
-  public CheckState state;
+  @Nullable public CheckState state;
   /** Fully qualified URL to detailed result on the Checker's service. */
   @Nullable public String url;
   /** Date/Time at which the checker started processing this check. */
diff --git a/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java b/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java
index c356056..f41517e 100644
--- a/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java
+++ b/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java
@@ -117,6 +117,16 @@
   }
 
   @Test
+  public void updateWithEmptyInput() throws Exception {
+    assertThat(
+            checksApiFactory
+                .revision(patchSetId)
+                .id(checkKey.checkerUuid())
+                .update(new CheckInput()))
+        .isNotNull();
+  }
+
+  @Test
   public void updateResultsInNewUpdatedTimestamp() throws Exception {
     CheckInput input = new CheckInput();
     input.state = CheckState.FAILED;