diff --git a/src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java b/src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java
index b481a99..56a4b92 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProvider.java
@@ -46,6 +46,7 @@
   private final String avatarRating;
   private final String gravatarUrl;
   private final String changeAvatarUrl;
+  private final boolean defaultImage;
 
   @Inject
   GravatarAvatarProvider(
@@ -69,25 +70,34 @@
       this.gravatarUrl =
           (canonicalUrl.startsWith("https://") ? "https://" : "http://") + gravatarUrlCfg;
     }
+
+    this.defaultImage = cfgFactory.getFromGerritConfig(pluginName).getBoolean("defaultImage", true);
   }
 
   @Override
   public String getUrl(IdentifiedUser forUser, int imageSize) {
-    if (forUser.getAccount().preferredEmail() == null) {
+    String preferredEmail = forUser.getAccount().preferredEmail();
+    if (preferredEmail == null && !defaultImage) {
       return null;
     }
-    final String email = forUser.getAccount().preferredEmail().trim().toLowerCase();
-    final byte[] emailMd5;
-    try {
-      MessageDigest digest = MessageDigest.getInstance("MD5");
-      emailMd5 = digest.digest(email.getBytes("UTF-8"));
-    } catch (UnsupportedEncodingException e) {
-      throw new RuntimeException("JVM lacks UTF-8 encoding", e);
-    } catch (NoSuchAlgorithmException e) {
-      throw new RuntimeException("MD5 digest not supported - required for Gravatar");
+
+    String emailMd5;
+    if (preferredEmail != null) {
+      final String email = preferredEmail.trim().toLowerCase();
+      try {
+        MessageDigest digest = MessageDigest.getInstance("MD5");
+        emailMd5 = hex(digest.digest(email.getBytes("UTF-8")));
+      } catch (UnsupportedEncodingException e) {
+        throw new RuntimeException("JVM lacks UTF-8 encoding", e);
+      } catch (NoSuchAlgorithmException e) {
+        throw new RuntimeException("MD5 digest not supported - required for Gravatar");
+      }
+    } else {
+      emailMd5 = "00000000000000000000000000000000";
     }
+
     StringBuilder url = new StringBuilder(gravatarUrl);
-    url.append(hex(emailMd5));
+    url.append(emailMd5);
     url.append(".jpg");
     url.append("?d=" + avatarType + "&r=" + avatarRating);
     if (imageSize > 0) {
diff --git a/src/main/resources/Documentation/config.md b/src/main/resources/Documentation/config.md
index d9a0f67..2112afb 100644
--- a/src/main/resources/Documentation/config.md
+++ b/src/main/resources/Documentation/config.md
@@ -40,3 +40,10 @@
 :	Link to where the avatar can be changed as displayed in the profile settings.
 
 	Default: http://www.gravatar.com
+
+<a id="defaultImage">
+`plugin.@PLUGIN@.defaultImage`
+:	Whether to have a default image placeholder when the account does not have
+	a default email.
+
+	Default: true
diff --git a/src/test/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProviderIT.java b/src/test/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProviderIT.java
new file mode 100644
index 0000000..c5634cb
--- /dev/null
+++ b/src/test/java/com/googlesource/gerrit/plugins/avatars/gravatar/GravatarAvatarProviderIT.java
@@ -0,0 +1,60 @@
+// Copyright (C) 2023 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.googlesource.gerrit.plugins.avatars.gravatar;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.gerrit.acceptance.LightweightPluginDaemonTest;
+import com.google.gerrit.acceptance.TestPlugin;
+import com.google.gerrit.acceptance.UseLocalDisk;
+import com.google.gerrit.acceptance.config.GerritConfig;
+import com.google.gerrit.entities.Account;
+import com.google.gerrit.server.IdentifiedUser;
+import com.google.gerrit.server.PropertyMap;
+import com.google.inject.AbstractModule;
+import com.google.inject.Inject;
+import org.junit.Test;
+
+@UseLocalDisk
+@TestPlugin(
+    name = "avatars-gravatar",
+    sysModule =
+        "com.googlesource.gerrit.plugins.avatars.gravatar.GravatarAvatarProviderIT$TestModule")
+public class GravatarAvatarProviderIT extends LightweightPluginDaemonTest {
+  private static final int IMAGE_SIZE = 100;
+
+  @Inject IdentifiedUser.GenericFactory userFactory;
+
+  public static class TestModule extends AbstractModule {}
+
+  @Test
+  public void accountWithoutEmailShouldHaveImageByDefault() {
+    assertThat(gravatarAvatar().getUrl(testUserWithoutEmail(), IMAGE_SIZE)).isNotNull();
+  }
+
+  @Test
+  @GerritConfig(name = "plugin.avatars-gravatar.defaultImage", value = "false")
+  public void accountWithoutEmailShouldDisableDefaultImage() {
+    assertThat(gravatarAvatar().getUrl(testUserWithoutEmail(), IMAGE_SIZE)).isNull();
+  }
+
+  private GravatarAvatarProvider gravatarAvatar() {
+    return plugin.getSysInjector().getInstance(GravatarAvatarProvider.class);
+  }
+
+  private IdentifiedUser testUserWithoutEmail() {
+    return userFactory.forTest(Account.id(1), PropertyMap.EMPTY);
+  }
+}