diff --git a/include/PR/ultratypes.h b/include/PR/ultratypes.h
index 6bc4c650..ad665164 100644
--- a/include/PR/ultratypes.h
+++ b/include/PR/ultratypes.h
@@ -59,6 +59,8 @@ typedef double				f64;	/* double prec floating point */
 
 typedef u32 size_t;
 
+typedef unsigned long int uintptr_t;
+
 typedef float Matrix[4][4];
 
 #endif  /* _LANGUAGE_C */
diff --git a/include/hardware.h b/include/hardware.h
new file mode 100644
index 00000000..f36bd8cb
--- /dev/null
+++ b/include/hardware.h
@@ -0,0 +1,9 @@
+#ifndef _HARDWARE_H_
+#define _HARDWARE_H_
+
+#define HW_REG(reg, type) *(volatile type *)(uintptr_t)((reg) | 0xa0000000)
+
+#define AI_STATUS_REG 0x0450000C
+#define AI_STATUS_AI_FULL (1 << 31)
+
+#endif
\ No newline at end of file
diff --git a/src/libultra/io/ai.c b/src/libultra/io/ai.c
index c3e6bbdc..41491008 100644
--- a/src/libultra/io/ai.c
+++ b/src/libultra/io/ai.c
@@ -1,12 +1,6 @@
 #include "global.h"
 #include "PR/rcp.h"
-
-// TODO: Put in proper header:
-typedef unsigned long int uintptr_t;
-
-#define HW_REG(reg, type) *(volatile type*)(uintptr_t)((reg) | 0xa0000000)
-#define AI_STATUS_REG 0x0450000C
-#define AI_STATUS_AI_FULL (1 << 31)
+#include "hardware.h"
 
 s32 __osAiDeviceBusy(void) {
     register s32 status = HW_REG(AI_STATUS_REG, u32);