diff --git a/java/com/google/gerrit/plugins/checks/CheckUpdate.java b/java/com/google/gerrit/plugins/checks/CheckUpdate.java
index 5813862..fd10148 100644
--- a/java/com/google/gerrit/plugins/checks/CheckUpdate.java
+++ b/java/com/google/gerrit/plugins/checks/CheckUpdate.java
@@ -39,20 +39,12 @@
   public abstract static class Builder {
     public abstract Builder setState(CheckState state);
 
-    public abstract Builder setState(Optional<CheckState> state);
-
     public abstract Builder setUrl(String url);
 
-    public abstract Builder setUrl(Optional<String> url);
-
     public abstract Builder setStarted(Timestamp started);
 
-    public abstract Builder setStarted(Optional<Timestamp> started);
-
     public abstract Builder setFinished(Timestamp finished);
 
-    public abstract Builder setFinished(Optional<Timestamp> finished);
-
     public abstract CheckUpdate build();
   }
 }
diff --git a/java/com/google/gerrit/plugins/checks/acceptance/testsuite/TestCheckUpdate.java b/java/com/google/gerrit/plugins/checks/acceptance/testsuite/TestCheckUpdate.java
index 3b0af57..3362cfb 100644
--- a/java/com/google/gerrit/plugins/checks/acceptance/testsuite/TestCheckUpdate.java
+++ b/java/com/google/gerrit/plugins/checks/acceptance/testsuite/TestCheckUpdate.java
@@ -49,6 +49,10 @@
 
     public abstract Builder setUrl(String url);
 
+    public Builder clearUrl() {
+      return setUrl("");
+    }
+
     public abstract Builder setStarted(Timestamp started);
 
     public abstract Builder setFinished(Timestamp finished);
diff --git a/java/com/google/gerrit/plugins/checks/api/PostCheck.java b/java/com/google/gerrit/plugins/checks/api/PostCheck.java
index aba0995..ad011d7 100644
--- a/java/com/google/gerrit/plugins/checks/api/PostCheck.java
+++ b/java/com/google/gerrit/plugins/checks/api/PostCheck.java
@@ -111,11 +111,24 @@
   }
 
   private static CheckUpdate toCheckUpdate(CheckInput input) throws BadRequestException {
-    return CheckUpdate.builder()
-        .setState(Optional.ofNullable(input.state))
-        .setUrl(input.url == null ? Optional.empty() : Optional.of(UrlValidator.clean(input.url)))
-        .setStarted(Optional.ofNullable(input.started))
-        .setFinished(Optional.ofNullable(input.finished))
-        .build();
+    CheckUpdate.Builder checkUpdateBuilder = CheckUpdate.builder();
+
+    if (input.state != null) {
+      checkUpdateBuilder.setState(input.state);
+    }
+
+    if (input.url != null) {
+      checkUpdateBuilder.setUrl(UrlValidator.clean(input.url));
+    }
+
+    if (input.started != null) {
+      checkUpdateBuilder.setStarted(input.started);
+    }
+
+    if (input.finished != null) {
+      checkUpdateBuilder.setFinished(input.finished);
+    }
+
+    return checkUpdateBuilder.build();
   }
 }
diff --git a/java/com/google/gerrit/plugins/checks/db/NoteDbCheck.java b/java/com/google/gerrit/plugins/checks/db/NoteDbCheck.java
index 8f6482a..2b52000 100644
--- a/java/com/google/gerrit/plugins/checks/db/NoteDbCheck.java
+++ b/java/com/google/gerrit/plugins/checks/db/NoteDbCheck.java
@@ -1,5 +1,6 @@
 package com.google.gerrit.plugins.checks.db;
 
+import com.google.common.base.Strings;
 import com.google.gerrit.common.Nullable;
 import com.google.gerrit.plugins.checks.Check;
 import com.google.gerrit.plugins.checks.CheckKey;
@@ -59,8 +60,8 @@
       state = update.state().get();
       modified = true;
     }
-    if (update.url().isPresent() && !update.url().get().equals(url)) {
-      url = update.url().get();
+    if (update.url().isPresent() && !update.url().get().equals(Strings.nullToEmpty(url))) {
+      url = Strings.emptyToNull(update.url().get());
       modified = true;
     }
     if (update.started().isPresent() && !update.started().get().equals(started)) {
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 2d97826..c39e68a 100644
--- a/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java
+++ b/javatests/com/google/gerrit/plugins/checks/acceptance/api/UpdateCheckIT.java
@@ -100,6 +100,17 @@
   }
 
   @Test
+  public void unsetUrl() throws Exception {
+    checkOperations.check(checkKey).forUpdate().setUrl("http://example.com/my-check").upsert();
+
+    CheckInput input = new CheckInput();
+    input.url = "";
+
+    CheckInfo info = checksApiFactory.revision(patchSetId).id(checkKey.checkerUuid()).update(input);
+    assertThat(info.url).isNull();
+  }
+
+  @Test
   public void cannotSetInvalidUrl() throws Exception {
     CheckInput input = new CheckInput();
     input.url = CheckTestData.INVALID_URL;
diff --git a/javatests/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImplTest.java b/javatests/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImplTest.java
index d2d6d42..500daf8 100644
--- a/javatests/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImplTest.java
+++ b/javatests/com/google/gerrit/plugins/checks/acceptance/testsuite/CheckOperationsImplTest.java
@@ -141,6 +141,16 @@
   }
 
   @Test
+  public void requestingNoUrlIsPossibleForCheckCreation() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).clearUrl().upsert();
+
+    CheckInfo check = getCheckFromServer(checkKey);
+    assertThat(check.url).isNull();
+  }
+
+  @Test
   public void specifiedStateIsRespectedForCheckCreation() throws Exception {
     CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
     CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
@@ -261,6 +271,17 @@
   }
 
   @Test
+  public void emptyUrlOfExistingCheckCanBeRetrieved() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).clearUrl().upsert();
+
+    Optional<String> url = checkOperations.check(checkKey).get().url();
+
+    assertThat(url).isEmpty();
+  }
+
+  @Test
   public void startedOfExistingCheckCanBeRetrieved() throws Exception {
     CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
     CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
@@ -361,6 +382,18 @@
   }
 
   @Test
+  public void urlCanBeCleared() throws Exception {
+    CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
+    CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);
+    checkOperations.newCheck(checkKey).setUrl("http://original-url").upsert();
+
+    checkOperations.check(checkKey).forUpdate().clearUrl().upsert();
+
+    Optional<String> currentUrl = checkOperations.check(checkKey).get().url();
+    assertThat(currentUrl).isEmpty();
+  }
+
+  @Test
   public void startedCanBeUpdated() throws Exception {
     CheckerUuid checkerUuid = checkerOperations.newChecker().repository(project).create();
     CheckKey checkKey = CheckKey.create(project, createChange().getPatchSetId(), checkerUuid);