diff --git a/src/vnet.am b/src/vnet.am
index 4de82cb517e..ddde879d296 100644
--- a/src/vnet.am
+++ b/src/vnet.am
@@ -509,6 +509,7 @@ nobase_include_HEADERS +=			\
  vnet/tcp/tcp_timer.h				\
  vnet/tcp/tcp_debug.h				\
  vnet/tcp/tcp.h					\
+ vnet/tcp/tcp_error.def				\
  vnet/tcp/tcp.api.h
 
 API_FILES += vnet/tcp/tcp.api