diff --git a/src/main/java/com/corundumstudio/socketio/protocol/PacketDecoder.java b/src/main/java/com/corundumstudio/socketio/protocol/PacketDecoder.java
index 1be5e58..f6a0f89 100644
--- a/src/main/java/com/corundumstudio/socketio/protocol/PacketDecoder.java
+++ b/src/main/java/com/corundumstudio/socketio/protocol/PacketDecoder.java
@@ -119,9 +119,10 @@ public class PacketDecoder {
     public Packet decodePackets(ByteBuf buffer, ClientHead client) throws IOException {
         if (isStringPacket(buffer)) {
             // TODO refactor
-            int headEndIndex = buffer.bytesBefore(10, (byte)-1);
+            int maxLength = Math.min(buffer.readableBytes(), 10);
+            int headEndIndex = buffer.bytesBefore(maxLength, (byte)-1);
             if (headEndIndex == -1) {
-                headEndIndex = buffer.bytesBefore(10, (byte)0x3f);
+                headEndIndex = buffer.bytesBefore(maxLength, (byte)0x3f);
             }
             int len = (int) readLong(buffer, headEndIndex);