diff --git a/libraries/AP_HAL_AVR_SITL/AP_HAL_AVR_SITL_Namespace.h b/libraries/AP_HAL_AVR_SITL/AP_HAL_AVR_SITL_Namespace.h
index a70396185a..a551c42e41 100644
--- a/libraries/AP_HAL_AVR_SITL/AP_HAL_AVR_SITL_Namespace.h
+++ b/libraries/AP_HAL_AVR_SITL/AP_HAL_AVR_SITL_Namespace.h
@@ -11,8 +11,9 @@ namespace AVR_SITL {
     class SITLAnalogIn; 
     class SITLRCInput;
     class SITLRCOutput;
-   class ADCSource;
+    class ADCSource;
     class RCInput;
+    class SITLUtil;
 }
 
 #endif // __AP_HAL_AVR_SITL_NAMESPACE_H__
diff --git a/libraries/AP_HAL_AVR_SITL/AnalogIn.cpp b/libraries/AP_HAL_AVR_SITL/AnalogIn.cpp
index 8de0b5ebe3..38939c8170 100644
--- a/libraries/AP_HAL_AVR_SITL/AnalogIn.cpp
+++ b/libraries/AP_HAL_AVR_SITL/AnalogIn.cpp
@@ -3,7 +3,6 @@
 #include <AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
 
-#include "HAL_AVR.h"
 #include "AP_HAL_AVR_SITL.h"
 #include "AnalogIn.h"
 #include <stdint.h>
diff --git a/libraries/AP_HAL_AVR_SITL/HAL_AVR_SITL_Class.cpp b/libraries/AP_HAL_AVR_SITL/HAL_AVR_SITL_Class.cpp
index 54fa029563..382a8a7e58 100644
--- a/libraries/AP_HAL_AVR_SITL/HAL_AVR_SITL_Class.cpp
+++ b/libraries/AP_HAL_AVR_SITL/HAL_AVR_SITL_Class.cpp
@@ -17,6 +17,7 @@
 #include "RCInput.h"
 #include "RCOutput.h"
 #include "SITL_State.h"
+#include "Util.h"
 
 #include <AP_HAL_Empty.h>
 #include <AP_HAL_Empty_Private.h>
@@ -40,6 +41,8 @@ static SITLUARTDriver sitlUart0Driver(0, &sitlState);
 static SITLUARTDriver sitlUart1Driver(1, &sitlState);
 static SITLUARTDriver sitlUart2Driver(2, &sitlState);
 
+static SITLUtil utilInstance;
+
 HAL_AVR_SITL::HAL_AVR_SITL() :
     AP_HAL::HAL(
 	    &sitlUart0Driver,  /* uartA */
@@ -53,7 +56,8 @@ HAL_AVR_SITL::HAL_AVR_SITL() :
         &emptyGPIO, /* gpio */
         &sitlRCInput,  /* rcinput */
         &sitlRCOutput, /* rcoutput */
-        &sitlScheduler), /* scheduler */
+        &sitlScheduler, /* scheduler */
+        &utilInstance), /* util */
     _sitl_state(&sitlState)
 {}
 
diff --git a/libraries/AP_HAL_AVR_SITL/Scheduler.cpp b/libraries/AP_HAL_AVR_SITL/Scheduler.cpp
index 4b3cf923bf..f273ca8423 100644
--- a/libraries/AP_HAL_AVR_SITL/Scheduler.cpp
+++ b/libraries/AP_HAL_AVR_SITL/Scheduler.cpp
@@ -3,7 +3,6 @@
 #include <AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
 
-#include "HAL_AVR.h"
 #include "AP_HAL_AVR_SITL.h"
 #include "Scheduler.h"
 #include <sys/time.h>
diff --git a/libraries/AP_HAL_AVR_SITL/Util.cpp b/libraries/AP_HAL_AVR_SITL/Util.cpp
new file mode 100644
index 0000000000..94e93d47cd
--- /dev/null
+++ b/libraries/AP_HAL_AVR_SITL/Util.cpp
@@ -0,0 +1,44 @@
+
+#include <AP_HAL.h>
+#if CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
+#include <stdio.h>
+#include <stdarg.h>
+
+int libc_vsnprintf(char* str, size_t size, const char *format, va_list ap) {
+    vsnprintf(str, size, format, ap);
+}
+
+#include "Util.h"
+using namespace AVR_SITL;
+
+int SITLUtil::snprintf(char* str, size_t size, const char *format, ...)
+{
+    va_list ap;
+    va_start(ap, format);
+    int res = libc_vsnprintf(str, size, format, ap);
+    va_end(ap);
+    return res;
+}
+
+int SITLUtil::snprintf_P(char* str, size_t size, const prog_char_t *format, ...)
+{
+    va_list ap;
+    va_start(ap, format);
+    int res = libc_vsnprintf(str, size, format, ap);
+    va_end(ap);
+    return res;
+}
+
+
+int SITLUtil::vsnprintf(char* str, size_t size, const char *format, va_list ap)
+{
+    return libc_vsnprintf(str, size, format, ap);
+}
+
+int SITLUtil::vsnprintf_P(char* str, size_t size, const prog_char_t *format,
+            va_list ap)
+{
+    return libc_vsnprintf(str, size, format, ap);
+}
+
+#endif // CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
diff --git a/libraries/AP_HAL_AVR_SITL/Util.h b/libraries/AP_HAL_AVR_SITL/Util.h
new file mode 100644
index 0000000000..4d055e2d41
--- /dev/null
+++ b/libraries/AP_HAL_AVR_SITL/Util.h
@@ -0,0 +1,17 @@
+
+#ifndef __AP_HAL_SITL_UTIL_H__
+#define __AP_HAL_SITL_UTIL_H__
+
+#include <AP_HAL.h>
+#include "AP_HAL_AVR_SITL_Namespace.h"
+
+class AVR_SITL::SITLUtil : public AP_HAL::Util {
+public:
+    int snprintf(char* str, size_t size, const char *format, ...);
+    int snprintf_P(char* str, size_t size, const prog_char_t *format, ...);
+    int vsnprintf(char* str, size_t size, const char *format, va_list ap);
+    int vsnprintf_P(char* str, size_t size, const prog_char_t *format,
+            va_list ap);
+};
+
+#endif // __AP_HAL_SITL_UTIL_H__
diff --git a/libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp b/libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp
index 00a5d28e16..7b7c0f0e71 100644
--- a/libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp
+++ b/libraries/AP_HAL_AVR_SITL/sitl_barometer.cpp
@@ -9,7 +9,6 @@
 #include <AP_HAL.h>
 #if CONFIG_HAL_BOARD == HAL_BOARD_AVR_SITL
 
-#include "HAL_AVR.h"
 #include "AP_HAL_AVR_SITL.h"
 
 using namespace AVR_SITL;