diff --git a/boards/common/iotlab/Makefile.include b/boards/common/iotlab/Makefile.include
index 137b5946c0..aa1afcaac1 100644
--- a/boards/common/iotlab/Makefile.include
+++ b/boards/common/iotlab/Makefile.include
@@ -3,7 +3,7 @@ PORT_LINUX ?= /dev/ttyUSB1
 PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.usbserial*B)))
 
 # setup serial terminal
-export BAUD = 500000
+BAUD = 500000
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # Using connect_assert_srst removes errors on flash from invalid state
diff --git a/boards/telosb/Makefile.include b/boards/telosb/Makefile.include
index 44af567b40..9bddb9d405 100644
--- a/boards/telosb/Makefile.include
+++ b/boards/telosb/Makefile.include
@@ -2,7 +2,7 @@
 PORT_LINUX ?= /dev/ttyUSB0
 PORT_DARWIN ?= $(firstword $(sort $(wildcard /dev/tty.usbserial-MXV*)))
 # setup serial terminal
-export BAUD ?= 9600
+BAUD ?= 9600
 include $(RIOTMAKE)/tools/serial.inc.mk
 
 # flash tool configuration