1 files changed, 3 insertions, 0 deletions
diff --git a/src/main/java/com/juick/www/api/SystemActivity.java b/src/main/java/com/juick/www/api/SystemActivity.java
index 36bc3ad4..59d5cc73 100644
--- a/src/main/java/com/juick/www/api/SystemActivity.java
+++ b/src/main/java/com/juick/www/api/SystemActivity.java
@@ -23,6 +23,8 @@ import com.juick.model.User;
 import java.util.Collections;
 import java.util.List;
 
+import javax.annotation.Nonnull;
+
 public class SystemActivity {
     private SystemActivity(ActivityType type) {
         this.type = type;
@@ -43,6 +45,7 @@ public class SystemActivity {
         return msg;
     }
 
+    @Nonnull
     public static SystemActivity read(User from, Message message) {
         var read = new SystemActivity(ActivityType.message);
         read.setFrom(from);