diff --git a/README.md b/README.md
index a2e042c..0de27c8 100644
--- a/README.md
+++ b/README.md
@@ -33,6 +33,11 @@ On Fedora:
        yum install perl-Device-SerialPort
        yum install perl-YAML
 
+On openSUSE:
+
+      zypper install perl-Device-SerialPort
+      zypper install perl-YAML
+
 On Mac using MacPorts:
 
        sudo port install p5-device-serialport
@@ -54,6 +59,13 @@ standard location for custom libraries when using the Arduino IDE), you need to
 set the `ARDUINO_SKETCHBOOK` variable to point to this directory. By default it
 is set to `$HOME/sketchbook`.
 
+## avrdude
+
+To upload compiled files, `avrdude` is used. This Makefile tries to find `avrdude` and it's config (`avrdude.conf`) below `ARDUINO_DIR`. If you like to use the one installed on your system instead of the one which came with Arduino, you can try to set the variables `AVRDUDE` and `AVRDUDE_CONF`. On a typical Linux system these could be set to
+
+      AVRDDUDE     = /usr/bin/avrdude
+      AVRDUDE_CONF = /etc/avrdude.conf
+
 ## Versioning
 
 The current version of the makefile is `0.12.0`. You can find the full history in the [HISTORY.md](HISTORY.md) file
diff --git a/arduino-mk/Arduino.mk b/arduino-mk/Arduino.mk
index b217592..aaec9aa 100644
--- a/arduino-mk/Arduino.mk
+++ b/arduino-mk/Arduino.mk
@@ -306,10 +306,12 @@ ifndef AVR_TOOLS_DIR
     BUNDLED_AVR_TOOLS_DIR := $(call dir_if_exists,$(ARDUINO_DIR)/hardware/tools/avr)
     ifdef BUNDLED_AVR_TOOLS_DIR
         AVR_TOOLS_DIR     = $(BUNDLED_AVR_TOOLS_DIR)
-        # The avrdude bundled with Arduino can't find it's config
-        AVRDUDE_CONF	  = $(AVR_TOOLS_DIR)/etc/avrdude.conf
-        $(call show_config_variable,AVR_TOOLS_DIR,[BUNDLED],(in Arduino distribution))
-
+        # if AVRDUDE_CONF is already defined, don't overwrite it
+        ifndef AVRDUDE_CONF
+            # The avrdude bundled with Arduino can't find it's config
+            AVRDUDE_CONF	  = $(AVR_TOOLS_DIR)/etc/avrdude.conf
+            $(call show_config_variable,AVR_TOOLS_DIR,[BUNDLED],(in Arduino distribution))
+       endif
     else
 
         SYSTEMPATH_AVR_TOOLS_DIR := $(call dir_if_exists,$(abspath $(dir $(shell which avr-gcc))/..))