diff --git a/lambda/Makefile b/lambda/Makefile
index 2f9afd6..7b8b09c 100644
--- a/lambda/Makefile
+++ b/lambda/Makefile
@@ -29,7 +29,7 @@
 
 PROGRAMMER_TYPE = avrisp
 # extra arguments to avrdude: baud rate, chip type, -F flag, etc.
-PROGRAMMER_ARGS = -b 19200 -P /dev/ttyACM0
+PROGRAMMER_ARGS = -b 19200 -P /dev/ttyACM3
 
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 ##########                   Makefile Magic!                    ##########