diff --git a/libraries/AP_Common/AP_Common.h b/libraries/AP_Common/AP_Common.h
index 0cfdbc3da1..8f5932b666 100644
--- a/libraries/AP_Common/AP_Common.h
+++ b/libraries/AP_Common/AP_Common.h
@@ -88,15 +88,22 @@ typedef struct {
   # undef PROGMEM
   # define PROGMEM __attribute__(())
  #else
+ #ifndef __PROG_TYPES_COMPAT__
   # undef PROGMEM
   # define PROGMEM __attribute__(( section(".progmem.data") ))
  #endif
+ #endif
 
  # undef PSTR
   /* Need const type for progmem - new for avr-gcc 4.6 */
   # if __AVR__ && __GNUC__ == 4 && __GNUC_MINOR__ > 5 
+ #ifdef __PROG_TYPES_COMPAT__
+ # define PSTR(s) (__extension__({static const char __c[] PROGMEM = (s); \
+                                   (const prog_char_t *)&__c[0]; }))
+ #else
  # define PSTR(s) (__extension__({static const prog_char __c[] PROGMEM = (s); \
                                   (const prog_char_t *)&__c[0]; }))
+ #endif
   #else
  # define PSTR(s) (__extension__({static prog_char __c[] PROGMEM = (s); \
                                   (prog_char_t *)&__c[0]; }))
@@ -107,7 +114,6 @@ typedef struct {
 // this gets the gcc __format__ checking right
 #define FPSTR(s) (wchar_t *)(s)
 
-
 static inline int        strcasecmp_P(const char *str1, const prog_char_t *pstr)
 {
     return strcasecmp_P(str1, (const prog_char *)pstr);
diff --git a/libraries/AP_Common/Arduino.mk b/libraries/AP_Common/Arduino.mk
index 381125f253..0f8f71bf0f 100644
--- a/libraries/AP_Common/Arduino.mk
+++ b/libraries/AP_Common/Arduino.mk
@@ -228,19 +228,19 @@ endif
 #
 # Tool options
 #
-DEFINES			=	-DF_CPU=$(F_CPU) -DARDUINO=$(ARDUINO_VERS) $(EXTRAFLAGS)
+DEFINES			=	-D__PROG_TYPES_COMPAT__ -DF_CPU=$(F_CPU) -DARDUINO=$(ARDUINO_VERS) $(EXTRAFLAGS)
 OPTFLAGS		=	-Os -Wformat -Wall -Wshadow -Wpointer-arith -Wcast-align -Wwrite-strings -Wformat=2 -Wno-reorder
 DEPFLAGS		=	-MD -MT $@
 
 # XXX warning options TBD
 CXXOPTS			= 	-mcall-prologues -ffunction-sections -fdata-sections -fno-exceptions
 COPTS			=	-mcall-prologues -ffunction-sections -fdata-sections
-ASOPTS			=	-assembler-with-cpp 
+ASOPTS			=	
 LISTOPTS		=	-adhlns=$(@:.o=.lst)
 
 CXXFLAGS		=	-g -mmcu=$(MCU) $(DEFINES) -Wa,$(LISTOPTS) $(OPTFLAGS) $(DEPFLAGS) $(CXXOPTS)
-CFLAGS			=	-g -mmcu=$(MCU) $(DEFINES) -Wa,$(LISTOPTS) $(OPTFLAGS) $(DEPFLAGS) $(COPTS)
-ASFLAGS			=	-g -mmcu=$(MCU) $(DEFINES)     $(LISTOPTS) $(DEPFLAGS) $(ASOPTS)
+CFLAGS			=	-g -mmcu=$(MCU) $(DEFINES) $(OPTFLAGS) $(DEPFLAGS) $(COPTS)
+ASFLAGS			=	-g -mmcu=$(MCU) $(DEFINES) $(DEPFLAGS) $(ASOPTS)
 LDFLAGS			=	-g -mmcu=$(MCU) $(OPTFLAGS) -Wl,--relax,--gc-sections -Wl,-Map -Wl,$(SKETCHMAP)
 
 ifeq ($(BOARD),mega)