diff --git a/codec/src/main/java/io/netty/handler/codec/LineBasedFrameDecoder.java b/codec/src/main/java/io/netty/handler/codec/LineBasedFrameDecoder.java
index ab49530de5..aee97d3c50 100644
--- a/codec/src/main/java/io/netty/handler/codec/LineBasedFrameDecoder.java
+++ b/codec/src/main/java/io/netty/handler/codec/LineBasedFrameDecoder.java
@@ -130,7 +130,7 @@ public class LineBasedFrameDecoder extends ByteToMessageDecoder {
                     fail(ctx, length);
                 }
             } else {
-                discardedBytes = buffer.readableBytes();
+                discardedBytes += buffer.readableBytes();
                 buffer.readerIndex(buffer.writerIndex());
             }
             return null;