diff --git a/src/main/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractor.java b/src/main/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractor.java
index 03bff09..b83f1c6 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractor.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/its/base/util/PropertyExtractor.java
@@ -116,7 +116,9 @@
   private Map<String,Set<String>> extractFrom(RefUpdatedEvent event,
       Set<Property> common) {
     common.add(propertyFactory.create("event-type", event.type));
-    common.addAll(propertyAttributeExtractor.extractFrom(event.submitter.get(), "submitter"));
+    if (event.submitter != null) {
+      common.addAll(propertyAttributeExtractor.extractFrom(event.submitter.get(), "submitter"));
+    }
     common.addAll(propertyAttributeExtractor.extractFrom(event.refUpdate.get()));
     return issueExtractor.getIssueIds(event.getProjectNameKey().get(),
         event.refUpdate.get().newRev);