diff --git a/Documentation/rest-api-projects.txt b/Documentation/rest-api-projects.txt
index a909ab4c44..45d33aef34 100644
--- a/Documentation/rest-api-projects.txt
+++ b/Documentation/rest-api-projects.txt
@@ -2329,7 +2329,7 @@ points. For annotated tags, the revision of the tag object.
 tag points.
 |`message`|Only set for annotated tags.|The tag message. For signed tags, includes
 the signature.
-|`tagger`|Only set for annotated tags.|The tagger as a
+|`tagger`|Only set for annotated tags, if present in the tag.|The tagger as a
 link:rest-api-changes.html#git-person-info[GitPersonInfo] entity.
 |=========================
 
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/ListTags.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/ListTags.java
index 3b1232b7d7..1a359c1f11 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/ListTags.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/ListTags.java
@@ -34,6 +34,7 @@ import com.google.inject.Singleton;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.errors.RepositoryNotFoundException;
 import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.Ref;
 import org.eclipse.jgit.lib.Repository;
 import org.eclipse.jgit.revwalk.RevObject;
@@ -132,14 +133,16 @@ public class ListTags implements RestReadView<ProjectResource> {
       throws MissingObjectException, IOException {
     RevObject object = rw.parseAny(ref.getObjectId());
     if (object instanceof RevTag) {
-      RevTag tag = (RevTag)object;
       // Annotated or signed tag
+      RevTag tag = (RevTag)object;
+      PersonIdent tagger = tag.getTaggerIdent();
       return new TagInfo(
           ref.getName(),
           tag.getName(),
           tag.getObject().getName(),
           tag.getFullMessage().trim(),
-          CommonConverters.toGitPerson(tag.getTaggerIdent()));
+          tagger != null ?
+              CommonConverters.toGitPerson(tag.getTaggerIdent()) : null);
     } else {
       // Lightweight tag
       return new TagInfo(