diff --git a/java/com/google/gerrit/plugins/checks/CheckerCreation.java b/java/com/google/gerrit/plugins/checks/CheckerCreation.java
index 1870b18..294f354 100644
--- a/java/com/google/gerrit/plugins/checks/CheckerCreation.java
+++ b/java/com/google/gerrit/plugins/checks/CheckerCreation.java
@@ -14,7 +14,10 @@
 
 package com.google.gerrit.plugins.checks;
 
+import static com.google.common.base.Preconditions.checkState;
+
 import com.google.auto.value.AutoValue;
+import com.google.common.annotations.VisibleForTesting;
 import com.google.gerrit.reviewdb.client.Project;
 
 @AutoValue
@@ -48,6 +51,20 @@
 
     public abstract Builder setRepository(Project.NameKey repository);
 
-    public abstract CheckerCreation build();
+    abstract CheckerCreation autoBuild();
+
+    public CheckerCreation build() {
+      CheckerCreation checkerCreation = autoBuild();
+      checkState(!checkerCreation.getName().trim().isEmpty(), "checker name cannot be empty");
+      checkState(
+          !checkerCreation.getRepository().get().trim().isEmpty(),
+          "repository name cannot be empty");
+      return checkerCreation;
+    }
+
+    @VisibleForTesting
+    public CheckerCreation buildWithoutValidationForTesting() {
+      return autoBuild();
+    }
   }
 }
diff --git a/java/com/google/gerrit/plugins/checks/CheckerUpdate.java b/java/com/google/gerrit/plugins/checks/CheckerUpdate.java
index 97165f6..463cb1d 100644
--- a/java/com/google/gerrit/plugins/checks/CheckerUpdate.java
+++ b/java/com/google/gerrit/plugins/checks/CheckerUpdate.java
@@ -14,7 +14,10 @@
 
 package com.google.gerrit.plugins.checks;
 
+import static com.google.common.base.Preconditions.checkState;
+
 import com.google.auto.value.AutoValue;
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.ImmutableSortedSet;
 import com.google.gerrit.plugins.checks.api.BlockingCondition;
 import com.google.gerrit.plugins.checks.api.CheckerStatus;
@@ -82,6 +85,27 @@
 
     public abstract Builder setQuery(String query);
 
-    public abstract CheckerUpdate build();
+    abstract CheckerUpdate autoBuild();
+
+    public CheckerUpdate build() {
+      CheckerUpdate checkerUpdate = autoBuild();
+
+      if (checkerUpdate.getName().isPresent()) {
+        checkState(!checkerUpdate.getName().get().trim().isEmpty(), "checker name cannot be empty");
+      }
+
+      if (checkerUpdate.getRepository().isPresent()) {
+        checkState(
+            !checkerUpdate.getRepository().get().get().trim().isEmpty(),
+            "repository name cannot be empty");
+      }
+
+      return checkerUpdate;
+    }
+
+    @VisibleForTesting
+    public CheckerUpdate buildWithoutValidationForTesting() {
+      return autoBuild();
+    }
   }
 }
diff --git a/javatests/com/google/gerrit/plugins/checks/CheckerCreationTest.java b/javatests/com/google/gerrit/plugins/checks/CheckerCreationTest.java
new file mode 100644
index 0000000..36968d3
--- /dev/null
+++ b/javatests/com/google/gerrit/plugins/checks/CheckerCreationTest.java
@@ -0,0 +1,83 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.plugins.checks;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.gerrit.testing.GerritJUnit.assertThrows;
+
+import com.google.gerrit.reviewdb.client.Project;
+import org.junit.Test;
+
+public class CheckerCreationTest {
+  private final CheckerUuid checkerUuid = CheckerUuid.parse("test:my-checker");
+  private final String checkerName = "My Checker";
+  private final Project.NameKey checkerRepository = Project.nameKey("my-repo");
+
+  @Test
+  public void nameCannotBeEmpty() {
+    IllegalStateException thrown =
+        assertThrows(
+            IllegalStateException.class,
+            () ->
+                CheckerCreation.builder()
+                    .setCheckerUuid(checkerUuid)
+                    .setName("")
+                    .setRepository(checkerRepository)
+                    .build());
+    assertThat(thrown).hasMessageThat().contains(String.format("checker name cannot be empty"));
+  }
+
+  @Test
+  public void nameCannotBeEmptyAfterTrim() {
+    IllegalStateException thrown =
+        assertThrows(
+            IllegalStateException.class,
+            () ->
+                CheckerCreation.builder()
+                    .setCheckerUuid(checkerUuid)
+                    .setName(" ")
+                    .setRepository(checkerRepository)
+                    .build());
+    assertThat(thrown).hasMessageThat().contains(String.format("checker name cannot be empty"));
+  }
+
+  @Test
+  public void repositoryCannotBeEmpty() {
+    IllegalStateException thrown =
+        assertThrows(
+            IllegalStateException.class,
+            () ->
+                CheckerCreation.builder()
+                    .setCheckerUuid(checkerUuid)
+                    .setName(checkerName)
+                    .setRepository(Project.nameKey(""))
+                    .build());
+    assertThat(thrown).hasMessageThat().contains(String.format("repository name cannot be empty"));
+  }
+
+  @Test
+  public void repositoryCannotBeEmptyAfterTrim() {
+    IllegalStateException thrown =
+        assertThrows(
+            IllegalStateException.class,
+            () ->
+                CheckerCreation.builder()
+                    .setCheckerUuid(checkerUuid)
+                    .setName(checkerName)
+                    .setRepository(Project.nameKey(" "))
+                    .build());
+    assertThat(thrown).hasMessageThat().contains(String.format("repository name cannot be empty"));
+  }
+}
diff --git a/javatests/com/google/gerrit/plugins/checks/CheckerUpdateTest.java b/javatests/com/google/gerrit/plugins/checks/CheckerUpdateTest.java
new file mode 100644
index 0000000..ae2ed4d
--- /dev/null
+++ b/javatests/com/google/gerrit/plugins/checks/CheckerUpdateTest.java
@@ -0,0 +1,57 @@
+// Copyright (C) 2019 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.plugins.checks;
+
+import static com.google.common.truth.Truth.assertThat;
+import static com.google.gerrit.testing.GerritJUnit.assertThrows;
+
+import com.google.gerrit.reviewdb.client.Project;
+import org.junit.Test;
+
+public class CheckerUpdateTest {
+  @Test
+  public void nameCannotBeEmpty() {
+    IllegalStateException thrown =
+        assertThrows(
+            IllegalStateException.class, () -> CheckerUpdate.builder().setName("").build());
+    assertThat(thrown).hasMessageThat().contains(String.format("checker name cannot be empty"));
+  }
+
+  @Test
+  public void nameCannotBeEmptyAfterTrim() {
+    IllegalStateException thrown =
+        assertThrows(
+            IllegalStateException.class, () -> CheckerUpdate.builder().setName(" ").build());
+    assertThat(thrown).hasMessageThat().contains(String.format("checker name cannot be empty"));
+  }
+
+  @Test
+  public void repositoryCannotBeEmpty() {
+    IllegalStateException thrown =
+        assertThrows(
+            IllegalStateException.class,
+            () -> CheckerUpdate.builder().setRepository(Project.nameKey("")).build());
+    assertThat(thrown).hasMessageThat().contains(String.format("repository name cannot be empty"));
+  }
+
+  @Test
+  public void repositoryCannotBeEmptyAfterTrim() {
+    IllegalStateException thrown =
+        assertThrows(
+            IllegalStateException.class,
+            () -> CheckerUpdate.builder().setRepository(Project.nameKey(" ")).build());
+    assertThat(thrown).hasMessageThat().contains(String.format("repository name cannot be empty"));
+  }
+}
diff --git a/javatests/com/google/gerrit/plugins/checks/db/CheckerConfigTest.java b/javatests/com/google/gerrit/plugins/checks/db/CheckerConfigTest.java
index 35c741f..a4d02b1 100644
--- a/javatests/com/google/gerrit/plugins/checks/db/CheckerConfigTest.java
+++ b/javatests/com/google/gerrit/plugins/checks/db/CheckerConfigTest.java
@@ -109,7 +109,8 @@
 
   @Test
   public void nameOfNewCheckerMustNotBeEmpty() throws Exception {
-    CheckerCreation checkerCreation = getPrefilledCheckerCreationBuilder().setName("").build();
+    CheckerCreation checkerCreation =
+        getPrefilledCheckerCreationBuilder().setName("").buildWithoutValidationForTesting();
     CheckerConfig checkerConfig =
         CheckerConfig.createForNewChecker(projectName, repository, checkerCreation);
 
@@ -232,7 +233,9 @@
   @Test
   public void repositoryOfNewCheckerMustNotBeEmpty() throws Exception {
     CheckerCreation checkerCreation =
-        getPrefilledCheckerCreationBuilder().setRepository(Project.nameKey("")).build();
+        getPrefilledCheckerCreationBuilder()
+            .setRepository(Project.nameKey(""))
+            .buildWithoutValidationForTesting();
     CheckerConfig checkerConfig =
         CheckerConfig.createForNewChecker(projectName, repository, checkerCreation);
 
@@ -319,7 +322,8 @@
   public void nameCannotBeRemoved() throws Exception {
     createArbitraryChecker(checkerUuid);
 
-    CheckerUpdate checkerUpdate = CheckerUpdate.builder().setName("").build();
+    CheckerUpdate checkerUpdate =
+        CheckerUpdate.builder().setName("").buildWithoutValidationForTesting();
 
     IOException thrown =
         assertThrows(IOException.class, () -> updateChecker(checkerUuid, checkerUpdate));
@@ -400,7 +404,9 @@
     createArbitraryChecker(checkerUuid);
 
     CheckerUpdate checkerUpdate =
-        CheckerUpdate.builder().setRepository(Project.nameKey("")).build();
+        CheckerUpdate.builder()
+            .setRepository(Project.nameKey(""))
+            .buildWithoutValidationForTesting();
 
     IOException thrown =
         assertThrows(IOException.class, () -> updateChecker(checkerUuid, checkerUpdate));