diff --git a/src/utility/tcp_states.h b/src/utility/tcp_states.h
new file mode 100644
index 00000000..ca3a4d83
--- /dev/null
+++ b/src/utility/tcp_states.h
@@ -0,0 +1,21 @@
+#ifndef TCP_STATES_H
+#define TCP_STATES_H
+
+#include "w5100.h"
+
+// common constants for client.state() return values
+enum tcp_state {
+  CLOSED      = SnSR::CLOSED,
+  LISTEN      = SnSR::LISTEN,
+  SYN_SENT    = SnSR::SYNSENT,
+  SYN_RCVD    = SnSR::SYNRECV,
+  ESTABLISHED = SnSR::ESTABLISHED,
+  FIN_WAIT_1  = SnSR::FIN_WAIT,
+  FIN_WAIT_2  = SnSR::FIN_WAIT,
+  CLOSE_WAIT  = SnSR::CLOSE_WAIT,
+  CLOSING     = SnSR::CLOSING,
+  LAST_ACK    = SnSR::LAST_ACK,
+  TIME_WAIT   = SnSR::TIME_WAIT
+};
+
+#endif