diff --git a/src/main/java/org/bukkit/craftbukkit/boss/CraftBossBar.java b/src/main/java/org/bukkit/craftbukkit/boss/CraftBossBar.java
index d98288cf79..9696fe5d02 100644
--- a/src/main/java/org/bukkit/craftbukkit/boss/CraftBossBar.java
+++ b/src/main/java/org/bukkit/craftbukkit/boss/CraftBossBar.java
@@ -103,13 +103,13 @@ public class CraftBossBar implements BossBar {
 
     @Override
     public void addFlag(BarFlag flag) {
-        flags.remove(flag);
+        flags.add(flag);
         updateFlags();
     }
 
     @Override
     public void removeFlag(BarFlag flag) {
-        flags.add(flag);
+        flags.remove(flag);
         updateFlags();
     }