diff --git a/ProtocolLib/pom.xml b/ProtocolLib/pom.xml
index ac7a8b99..586f9634 100644
--- a/ProtocolLib/pom.xml
+++ b/ProtocolLib/pom.xml
@@ -2,7 +2,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.comphenix.protocol</groupId>
   <artifactId>ProtocolLib</artifactId>
-  <version>2.3.0</version>
+  <version>2.3.1-SNAPSHOT</version>
   <packaging>jar</packaging>
   <description>Provides read/write access to the Minecraft protocol.</description>
   
@@ -219,16 +219,16 @@
 		<scope>test</scope>
 	</dependency>
 	<dependency>
-    	<groupId>org.powermock</groupId>
-    	<artifactId>powermock-module-junit4</artifactId>
-    	<version>${powermock.version}</version>
-    	<scope>test</scope>
-  	</dependency>
-  	<dependency>
-    	<groupId>org.powermock</groupId>
-    	<artifactId>powermock-api-mockito</artifactId>
-    	<version>${powermock.version}</version>
-    	<scope>test</scope>
-  	</dependency> 
+  		<groupId>org.powermock</groupId>
+  		<artifactId>powermock-module-junit4</artifactId>
+  		<version>${powermock.version}</version>
+  		<scope>test</scope>
+	</dependency>
+	<dependency>
+		<groupId>org.powermock</groupId>
+		<artifactId>powermock-api-mockito</artifactId>
+		<version>${powermock.version}</version>
+		<scope>test</scope>
+	</dependency> 
   </dependencies>
 </project>
\ No newline at end of file
diff --git a/ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/NetworkServerInjector.java b/ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/NetworkServerInjector.java
index 16218066..ef6858bc 100644
--- a/ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/NetworkServerInjector.java
+++ b/ProtocolLib/src/main/java/com/comphenix/protocol/injector/player/NetworkServerInjector.java
@@ -20,6 +20,8 @@ package com.comphenix.protocol.injector.player;
 import java.lang.reflect.Field;
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
+import java.util.Arrays;
+
 import net.sf.cglib.proxy.*;
 
 import org.bukkit.entity.Player;
@@ -45,8 +47,8 @@ import com.comphenix.protocol.utility.MinecraftReflection;
  * @author Kristian
  */
 class NetworkServerInjector extends PlayerInjector {
-
 	private volatile static CallbackFilter callbackFilter;
+	private volatile static boolean foundSendPacket;
 	
 	private volatile static Field disconnectField;
 	private InjectedServerConnection serverInjection;
@@ -168,10 +170,12 @@ class NetworkServerInjector extends PlayerInjector {
 			callbackFilter = new CallbackFilter() {
 				@Override
 				public int accept(Method method) {
-					if (method.equals(sendPacket))
+					if (isCallableEqual(sendPacket, method)) {
+						foundSendPacket = true;
 						return 0;
-					else
+					} else {
 						return 1;
+					}
 				}
 			};
 		}
@@ -204,9 +208,11 @@ class NetworkServerInjector extends PlayerInjector {
 		
 		// Inject it now
 		if (proxyObject != null) {
-			// This will be done by InjectedServerConnection instead
-			//copyTo(serverHandler, proxyObject);
-			
+			// Did we override a sendPacket method?
+			if (!foundSendPacket) {
+				throw new IllegalArgumentException("Unable to find a sendPacket method in " + serverClass);
+			}
+
 			serverInjection.replaceServerHandler(serverHandler, proxyObject);
 			serverHandlerRef.setValue(proxyObject);
 			return true;
@@ -215,6 +221,20 @@ class NetworkServerInjector extends PlayerInjector {
 		}
 	}
 	
+	/**
+	 * Determine if the two methods are equal in terms of call semantics.
+	 * <p>
+	 * Two methods are equal if they have the same name, parameter types and return type.
+	 * @param first - first method.
+	 * @param second - second method.
+	 * @return TRUE if they are, FALSE otherwise.
+	 */
+	private boolean isCallableEqual(Method first, Method second) {
+		return first.getName().equals(second.getName()) &&
+			   first.getReturnType().equals(second.getReturnType()) &&
+			   Arrays.equals(first.getParameterTypes(), second.getParameterTypes());
+	}
+	
 	private Object getProxyServerHandler() {
 		if (proxyServerField != null && !proxyServerField.equals(serverHandlerRef.getField())) {
 			try {
diff --git a/ProtocolLib/src/main/resources/plugin.yml b/ProtocolLib/src/main/resources/plugin.yml
index 23fb34bf..c95bbdcf 100644
--- a/ProtocolLib/src/main/resources/plugin.yml
+++ b/ProtocolLib/src/main/resources/plugin.yml
@@ -1,5 +1,5 @@
 name: ProtocolLib
-version: 2.3.0
+version: 2.3.1-SNAPSHOT
 description: Provides read/write access to the Minecraft protocol.
 author: Comphenix
 website: http://www.comphenix.net/ProtocolLib