diff --git a/boards/opencm904/Makefile.include b/boards/opencm904/Makefile.include
index 7c329c7fba..8ce69924a1 100644
--- a/boards/opencm904/Makefile.include
+++ b/boards/opencm904/Makefile.include
@@ -8,7 +8,7 @@ export DEBUGGER =
 export DEBUGSERVER =
 
 HEXFILE = $(BINFILE)
-export FFLAGS =
+export FFLAGS = $(PORT) $(HEXFILE)
 export DEBUGGER_FLAGS =
 
 # define the default port depending on the host OS
diff --git a/boards/opencm904/dist/robotis-loader.py b/boards/opencm904/dist/robotis-loader.py
index 94ba9f590d..a5cfd78805 100755
--- a/boards/opencm904/dist/robotis-loader.py
+++ b/boards/opencm904/dist/robotis-loader.py
@@ -57,13 +57,9 @@ else:
 
 
 # Reading command line
-# if len(sys.argv) != 3:
-#     exit('! Usage: robotis-loader.py <serial-port> <binary>')
-# pgm, port, binary = sys.argv
-
-pgm = sys.argv[0]
-port = os.environ["PORT"]
-binary = os.environ["HEXFILE"]
+if len(sys.argv) != 3:
+    exit('! Usage: robotis-loader.py <serial-port> <binary>')
+pgm, port, binary = sys.argv
 
 
 def progressBar(percent, precision=65):