diff --git a/src/main/java/net/frozenorb/apiv3/model/Rank.java b/src/main/java/net/frozenorb/apiv3/model/Rank.java
index 6b1971e..a679b97 100644
--- a/src/main/java/net/frozenorb/apiv3/model/Rank.java
+++ b/src/main/java/net/frozenorb/apiv3/model/Rank.java
@@ -40,7 +40,7 @@ public final class Rank {
 	}
 
 	public static Rank findById(String id) {
-		return rankIdCache.get(id.toLowerCase());
+		return id == null ? null : rankIdCache.get(id.toLowerCase());
 	}
 
 	static {
diff --git a/src/main/java/net/frozenorb/apiv3/model/Server.java b/src/main/java/net/frozenorb/apiv3/model/Server.java
index 2240ec2..b494236 100644
--- a/src/main/java/net/frozenorb/apiv3/model/Server.java
+++ b/src/main/java/net/frozenorb/apiv3/model/Server.java
@@ -39,7 +39,7 @@ public final class Server {
 	}
 
 	public static Server findById(String id) {
-		return serverIdCache.get(id.toLowerCase());
+		return id == null ? null : serverIdCache.get(id.toLowerCase());
 	}
 
 	static {
diff --git a/src/main/java/net/frozenorb/apiv3/model/ServerGroup.java b/src/main/java/net/frozenorb/apiv3/model/ServerGroup.java
index 31c819d..8cb5476 100644
--- a/src/main/java/net/frozenorb/apiv3/model/ServerGroup.java
+++ b/src/main/java/net/frozenorb/apiv3/model/ServerGroup.java
@@ -37,7 +37,7 @@ public final class ServerGroup {
 	}
 
 	public static ServerGroup findById(String id) {
-		return serverGroupIdCache.get(id.toLowerCase());
+		return id == null ? null : serverGroupIdCache.get(id.toLowerCase());
 	}
 
 	public static ServerGroup findDefault() {