diff --git a/hardware/arduino/avr/platform.txt b/hardware/arduino/avr/platform.txt
index 0223ccae7..fa588746f 100644
--- a/hardware/arduino/avr/platform.txt
+++ b/hardware/arduino/avr/platform.txt
@@ -102,7 +102,7 @@ tools.avrdude.upload.params.quiet=-q -q
 # tools.avrdude.upload.verify is needed for backwards compatibility with IDE 1.6.8 or older, IDE 1.6.9 or newer overrides this value
 tools.avrdude.upload.verify=
 tools.avrdude.upload.params.noverify=-V
-tools.avrdude.upload.pattern="{cmd.path}" "-C{config.path}" {upload.verbose} {upload.verify} -p{build.mcu} -c{upload.protocol} -P{serial.port} -b{upload.speed} -D "-Uflash:w:{build.path}/{build.project_name}.hex:i"
+tools.avrdude.upload.pattern="{cmd.path}" "-C{config.path}" {upload.verbose} {upload.verify} -p{build.mcu} -c{upload.protocol} "-P{serial.port}" -b{upload.speed} -D "-Uflash:w:{build.path}/{build.project_name}.hex:i"
 
 tools.avrdude.program.params.verbose=-v
 tools.avrdude.program.params.quiet=-q -q