diff --git a/src/main/java/me/clip/placeholderapi/PlaceholderHook.java b/src/main/java/me/clip/placeholderapi/PlaceholderHook.java
index 91c3263..268ee86 100644
--- a/src/main/java/me/clip/placeholderapi/PlaceholderHook.java
+++ b/src/main/java/me/clip/placeholderapi/PlaceholderHook.java
@@ -23,9 +23,11 @@ package me.clip.placeholderapi;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.entity.Player;
 import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
 
 public abstract class PlaceholderHook {
 
+  @Nullable
   public String onRequest(final OfflinePlayer player, @NotNull final String params) {
     if (player != null && player.isOnline()) {
       return onPlaceholderRequest((Player) player, params);
@@ -34,6 +36,7 @@ public abstract class PlaceholderHook {
     return onPlaceholderRequest(null, params);
   }
 
+  @Nullable
   public String onPlaceholderRequest(final Player player, @NotNull final String params) {
     return null;
   }