diff --git a/man7/tcp.7 b/man7/tcp.7
index 382308ec0..c23bf29e9 100644
--- a/man7/tcp.7
+++ b/man7/tcp.7
@@ -322,6 +322,13 @@ The algorithm "reno" is always available,
 but additional choices may be available depending on kernel configuration.
 The default value for this file is set as part of kernel configuration.
 .TP
+.IR tcp_dma_copybreak " (integer; default: 4096; since Linux 2.6.24)"
+Lower limit, in bytes, of the size of socket reads that will be
+offloaded to a DMA copy engine, if one is present in the system
+and the kernel was configured with the
+.B CONFIG_NET_DMA
+option.
+.TP
 .IR tcp_dsack " (Boolean; default: enabled; since Linux 2.4)"
 .\" Since 2.4.0-test7
 Enable RFC\ 2883 TCP Duplicate SACK support.