diff --git a/source/common/http/sidestream_watermark.h b/source/common/http/sidestream_watermark.h
index 21a3e2f46ae5..c41bf2380ab5 100644
--- a/source/common/http/sidestream_watermark.h
+++ b/source/common/http/sidestream_watermark.h
@@ -35,7 +35,7 @@ class StreamFilterSidestreamWatermarkCallbacks : public Http::SidestreamWatermar
 
   /**
    * The set function needs to be called by stream decoder filter before side stream connection is
-   * established, to apply the backpressure to downsream when it is above watermark,
+   * established, to apply the backpressure to downstream when it is above watermark,
    */
   void setDecoderFilterCallbacks(Http::StreamDecoderFilterCallbacks* decode_callback) {
     decode_callback_ = decode_callback;