diff --git a/codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameWriter.java b/codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameWriter.java
index e13a631c31..6ef92018bc 100644
--- a/codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameWriter.java
+++ b/codec-http2/src/main/java/io/netty/handler/codec/http2/DefaultHttp2FrameWriter.java
@@ -310,7 +310,7 @@ public class DefaultHttp2FrameWriter implements Http2FrameWriter, Http2FrameSize
         try {
             checkNotNull(settings, "settings");
             int payloadLength = SETTING_ENTRY_LENGTH * settings.size();
-            ByteBuf buf = ctx.alloc().buffer(FRAME_HEADER_LENGTH + settings.size() * SETTING_ENTRY_LENGTH);
+            ByteBuf buf = ctx.alloc().buffer(FRAME_HEADER_LENGTH + payloadLength);
             writeFrameHeaderInternal(buf, payloadLength, SETTINGS, new Http2Flags(), 0);
             for (Http2Settings.PrimitiveEntry<Long> entry : settings.entries()) {
                 buf.writeChar(entry.key());