diff --git a/tests/gnrc_tcp_client/Makefile b/tests/gnrc_tcp_client/Makefile
index 4521cf4ebc4367381ead41e8d3cd8b9a63bcaa91..00ed0218e39dec2779ba6357f96f0b183128f9ac 100644
--- a/tests/gnrc_tcp_client/Makefile
+++ b/tests/gnrc_tcp_client/Makefile
@@ -2,7 +2,10 @@ include ../Makefile.tests_common
 
 # If no BOARD is found in the environment, use this default:
 BOARD ?= native
-PORT ?= tap1
+
+ifeq (native,$(BOARD))
+  PORT ?= tap1
+endif
 
 TCP_TARGET_ADDR ?= fe80::affe%5
 TCP_TARGET_PORT ?= 80
diff --git a/tests/gnrc_tcp_server/Makefile b/tests/gnrc_tcp_server/Makefile
index 83dc0421c8d724711e16e6ecdb43b6f1e053c88f..8f95273e374dbf5ee93cc4b77a741c667636b156 100644
--- a/tests/gnrc_tcp_server/Makefile
+++ b/tests/gnrc_tcp_server/Makefile
@@ -2,7 +2,10 @@ include ../Makefile.tests_common
 
 # If no BOARD is found in the environment, use this default:
 BOARD ?= native
-PORT ?= tap0
+
+ifeq (native,$(BOARD))
+  PORT ?= tap0
+endif
 
 TCP_LOCAL_ADDR ?= fe80::affe
 TCP_LOCAL_PORT ?= 80