diff --git a/src/stk500.h b/src/stk500.h
index 32cc23b9..b5bbfd45 100644
--- a/src/stk500.h
+++ b/src/stk500.h
@@ -23,24 +23,23 @@
 extern "C" {
 #endif
 
-extern const char stk500_desc[];
-void stk500_initpgm(PROGRAMMER *pgm);
+  extern const char stk500_desc[];
+  void stk500_initpgm(PROGRAMMER *pgm);
 
-/* used by arduino.c to avoid duplicate code */
-int stk500_getsync(const PROGRAMMER *pgm);
-int stk500_drain(const PROGRAMMER *pgm, int display);
+  // Used by arduino.c to avoid duplicate code
+  int stk500_getsync(const PROGRAMMER *pgm);
+  int stk500_drain(const PROGRAMMER *pgm, int display);
 
 #ifdef __cplusplus
 }
 #endif
 
 #include "xbee.h"
-
 struct pdata {
   unsigned char ext_addr_byte;  // Record ext-addr byte set in the target device (if used)
   int retry_attempts;           // Number of connection attempts provided by the user
   int xbeeResetPin;             // Piggy back variable used by xbee programmmer
-  struct serial_device xbee_serdev; // Piggy back device descriptor for XBee framing
+  struct serial_device xbee_serdev;     // Piggy back device descriptor for XBee framing
 
   // Get/set flags for adjustable target voltage
   bool vtarg_get;
@@ -64,7 +63,4 @@ struct pdata {
 };
 
 #define PDATA(pgm) ((struct pdata *)(pgm->cookie))
-
 #endif
-
-