diff --git a/src/main/java/io/github/thebusybiscuit/slimefun4/integrations/PlaceholderAPIIntegration.java b/src/main/java/io/github/thebusybiscuit/slimefun4/integrations/PlaceholderAPIIntegration.java
index 52a9618aa7..b4d966ed57 100644
--- a/src/main/java/io/github/thebusybiscuit/slimefun4/integrations/PlaceholderAPIIntegration.java
+++ b/src/main/java/io/github/thebusybiscuit/slimefun4/integrations/PlaceholderAPIIntegration.java
@@ -11,6 +11,7 @@
 import me.clip.placeholderapi.expansion.PlaceholderExpansion;
 import org.bukkit.OfflinePlayer;
 import org.bukkit.entity.Player;
+import org.jetbrains.annotations.NotNull;
 
 /**
  * This is our integration for {@link PlaceholderAPI}.
@@ -28,17 +29,17 @@ public PlaceholderAPIIntegration(Slimefun plugin) {
     }
 
     @Override
-    public String getIdentifier() {
+    public @NotNull String getIdentifier() {
         return "slimefun";
     }
 
     @Override
-    public String getVersion() {
+    public @NotNull String getVersion() {
         return version;
     }
 
     @Override
-    public String getAuthor() {
+    public @NotNull String getAuthor() {
         return author;
     }