diff --git a/makefiles/tools/openocd.inc.mk b/makefiles/tools/openocd.inc.mk
index f86c1bd4d9..4d01fb0174 100644
--- a/makefiles/tools/openocd.inc.mk
+++ b/makefiles/tools/openocd.inc.mk
@@ -13,7 +13,9 @@ RESET_FLAGS ?= reset
 
 ifneq (,$(OPENOCD_DEBUG_ADAPTER))
   include $(RIOTMAKE)/tools/openocd-adapters/$(OPENOCD_DEBUG_ADAPTER).inc.mk
-  OPENOCD_ADAPTER_INIT += -c 'transport select $(OPENOCD_TRANSPORT)'
+  ifneq (default,$(OPENOCD_TRANSPORT))
+    OPENOCD_ADAPTER_INIT += -c 'transport select $(OPENOCD_TRANSPORT)'
+  endif
 endif
 
 OPENOCD_CONFIG ?= $(BOARDDIR)/dist/openocd.cfg