diff --git a/DEVELOPER.md b/DEVELOPER.md
index 81e5fec0..1748fdb1 100644
--- a/DEVELOPER.md
+++ b/DEVELOPER.md
@@ -12,12 +12,13 @@ make tox
 
 ## Running an individual APIO test
 
-Run from the repo root. Replace with the path to the desire test.
+Run from the repo root. Replace with the path to the desire test. Running ``pytest`` alone runs all the tests.
 
 ```shell
-test/code_commands/test_build.py
+pytest test/code_commands/test_build.py
 ```
 
+
 ## Running APIO in a debugger
 
 Set the debugger to run the ``apio_run.py`` main with the regular ``apio`` arguments. Set the project directory ot the project file or use the ``--project_dir`` apio argument to point to the project directory.
diff --git a/apio/managers/scons.py b/apio/managers/scons.py
index be6b0084..2891ce7b 100644
--- a/apio/managers/scons.py
+++ b/apio/managers/scons.py
@@ -254,7 +254,8 @@ def get_programmer(self, board: str, prog: dict) -> str:
             * sram: Perform SRAM programming
             * flash: Perform Flash programming
 
-        * OUTPUT: A string with the command+args to execute
+        * OUTPUT: A string with the command+args to execute and a ${SOURCE}
+          placeholder for the bitstream file name.
         """
 
         # -- Return string to create
@@ -306,9 +307,12 @@ def get_programmer(self, board: str, prog: dict) -> str:
         # --   * "${PID}" (optional): USB Product id
         # --   * "${FTDI_ID}" (optional): FTDI id
         # --   * "${SERIAL_PORT}" (optional): Serial port name
+        # --   * "${SOURCE}" (required): Bitstream file name.
         programmer = self.serialize_programmer(
             board_data, prog[SRAM], prog[FLASH]
         )
+        # -- The placeholder for the bitstream file name should always exist.
+        assert "${SOURCE}" in programmer, programmer
 
         # -- Assign the parameters in the Template string
 
@@ -358,7 +362,9 @@ def get_programmer(self, board: str, prog: dict) -> str:
             programmer = programmer.replace("${SERIAL_PORT}", device)
 
         # -- Return the Command to execute for uploading the circuit
-        # -- to the given board
+        # -- to the given board. Scons will replace ${SOURCE} with the
+        # -- bitstream file name before executing the command.
+        assert "${SOURCE}" in programmer, programmer
         return programmer
 
     @staticmethod
@@ -508,8 +514,8 @@ def serialize_programmer(
            * "${SERIAL_PORT}" (optional): Serial port name
 
           Example of output strings:
-          "'tinyprog --pyserial -c ${SERIAL_PORT} --program'"
-          "'iceprog -d i:0x${VID}:0x${PID}:${FTDI_ID}'"
+          "'tinyprog --pyserial -c ${SERIAL_PORT} --program ${SOURCE}'"
+          "'iceprog -d i:0x${VID}:0x${PID}:${FTDI_ID} ${SOURCE}'"
         """
 
         # -- Get the programmer type
@@ -534,6 +540,11 @@ def serialize_programmer(
         if content.get("args"):
             programmer += f" {content['args']}"
 
+        # -- Mark the expected location of the bitstream file name, before
+        # -- we appened any arg to the command. Some programmers such as
+        # -- dfu-util require it immediatly after the "args" string.
+        programmer += " ${SOURCE}"
+
         # -- Some tools need extra arguments
         # -- (like dfu-util for example)
         if prog_info.get("extra_args"):
diff --git a/apio/resources/ecp5/SConstruct b/apio/resources/ecp5/SConstruct
index 7bcbc9dc..1dddf9e2 100644
--- a/apio/resources/ecp5/SConstruct
+++ b/apio/resources/ecp5/SConstruct
@@ -170,7 +170,9 @@ build_target = env.Alias('build', bitstream_target)
 AlwaysBuild(build_target)
 
 # -- Upload the bitstream into FPGA
-upload_target = env.Alias('upload', bitstream_target, '{0} $SOURCE'.format(PROG))
+assert "${SOURCE}" in PROG
+programmer = PROG.replace("${SOURCE}", "$SOURCE")
+upload_target = env.Alias('upload', bitstream_target)
 AlwaysBuild(upload_target)
 
 # -- Target time: calculate the time
diff --git a/apio/resources/gowin/SConstruct b/apio/resources/gowin/SConstruct
index b14c78cb..fcc97734 100644
--- a/apio/resources/gowin/SConstruct
+++ b/apio/resources/gowin/SConstruct
@@ -178,7 +178,9 @@ if(VERBOSE_ALL or VERBOSE_PNR):
     AlwaysBuild(asc_target)
 
 # -- Upload the bitstream into FPGA
-upload_target = env.Alias('upload', bitstream_target, '{0} $SOURCE'.format(PROG))
+assert "${SOURCE}" in PROG
+programmer = PROG.replace("${SOURCE}", "$SOURCE")
+upload_target = env.Alias('upload', bitstream_target, programmer)
 AlwaysBuild(upload_target)
 
 # -- Target time: calculate the time
diff --git a/apio/resources/ice40/SConstruct b/apio/resources/ice40/SConstruct
index a7f8c2a6..e6c7d4e6 100644
--- a/apio/resources/ice40/SConstruct
+++ b/apio/resources/ice40/SConstruct
@@ -175,7 +175,9 @@ if(VERBOSE_ALL or VERBOSE_PNR):
     AlwaysBuild(asc_target)
 
 # -- Upload the bitstream into FPGA
-upload_target = env.Alias('upload', bitstream_target, '{0} $SOURCE'.format(PROG))
+assert "${SOURCE}" in PROG
+programmer = PROG.replace("${SOURCE}", "$SOURCE")
+upload_target = env.Alias('upload', bitstream_target, programmer)
 AlwaysBuild(upload_target)
 
 # -- Target time: calculate the time