diff --git a/src/pia.h b/src/pia.h
index 1d9e17d..aacb6d6 100644
--- a/src/pia.h
+++ b/src/pia.h
@@ -12,10 +12,10 @@
 #include <v6502/cpu.h>
 #include <curses.h>
 
-#define A1PIA_KEYBOARD_INPUT_REGISTER	0xD010
-#define A1PIA_KEYBOARD_READY_REGISTER	0xD011
-#define A1PIA_VIDEO_OUTPUT_REGISTER		0xD012
-#define A1PIA_VIDEO_ATTR_REGISTER		0xD013
+#define A1PIA_KEYBOARD_INPUT_REGISTER 0xD010
+#define A1PIA_KEYBOARD_READY_REGISTER 0xD011
+#define A1PIA_VIDEO_OUTPUT_REGISTER   0xD012
+#define A1PIA_VIDEO_ATTR_REGISTER     0xD013
 
 typedef struct {
 	/** @brief Curses output object */