diff --git a/src/shrpx.h b/src/shrpx.h
index 89ab5993..c7e050fb 100644
--- a/src/shrpx.h
+++ b/src/shrpx.h
@@ -36,6 +36,6 @@
 #define DIE()                                   \
   assert(0);
 
-#define SHRPX_READ_WATERMARK (64*1024)
+#define SHRPX_READ_WATERMARK (16 * 1024)
 
 #endif // SHRPX_H