diff --git a/arduino-mk/Arduino.mk b/arduino-mk/Arduino.mk
index a091b2b..0ea464b 100644
--- a/arduino-mk/Arduino.mk
+++ b/arduino-mk/Arduino.mk
@@ -285,8 +285,6 @@ ifdef ARDUINO_DIR
 
 ifndef AVR_TOOLS_DIR
 AVR_TOOLS_DIR     = $(ARDUINO_DIR)/hardware/tools/avr
-# The avrdude bundled with Arduino can't find it's config
-AVRDUDE_CONF	  = $(AVR_TOOLS_DIR)/etc/avrdude.conf
 endif
 
 ifndef AVR_TOOLS_PATH
@@ -612,6 +610,14 @@ ifndef AVRDUDE
 AVRDUDE          = $(AVR_TOOLS_PATH)/avrdude
 endif
 
+ifndef AVRDUDE_CONF
+ifndef AVR_TOOLS_DIR
+# The avrdude bundled with Arduino can't find its config
+AVRDUDE_CONF	  = $(AVR_TOOLS_DIR)/etc/avrdude.conf
+endif
+# If avrdude is installed separately, it can find its own config flie
+endif
+
 AVRDUDE_COM_OPTS = -q -V -p $(MCU)
 ifdef AVRDUDE_CONF
 AVRDUDE_COM_OPTS += -C $(AVRDUDE_CONF)