diff --git a/aoc_functions.h b/aoc_functions.h
index 79a95d4..f2e8205 100644
--- a/aoc_functions.h
+++ b/aoc_functions.h
@@ -28,6 +28,8 @@
 extern "C" {
 #endif
 
+#include <gctypes.h>
+
 extern u32 aoc_handle;
 
 #define AOC_TITLE_SIZE              104
diff --git a/gx2_functions.h b/gx2_functions.h
index 37521c8..9133fcc 100644
--- a/gx2_functions.h
+++ b/gx2_functions.h
@@ -28,6 +28,7 @@
 extern "C" {
 #endif
 
+#include <gctypes.h>
 #include "gx2_types.h"
 
 extern u32 gx2_handle;
diff --git a/sys_functions.h b/sys_functions.h
index 167a2a4..e448410 100644
--- a/sys_functions.h
+++ b/sys_functions.h
@@ -28,6 +28,8 @@
 extern "C" {
 #endif
 
+#include <gctypes.h>
+
 extern u32 sysapp_handle;
 
 void InitSysFunctionPointers(void);
diff --git a/syshid_functions.h b/syshid_functions.h
index 6800ae4..9e29133 100644
--- a/syshid_functions.h
+++ b/syshid_functions.h
@@ -28,20 +28,22 @@
 extern "C" {
 #endif
 
+#include <gctypes.h>
+
 extern u32 syshid_handle;
 
 typedef struct
 {
     u32 handle;
     u32 physical_device_inst;
-    unsigned short vid;
-    unsigned short pid;
-    unsigned char interface_index;
-    unsigned char sub_class;
-    unsigned char protocol;
+    u16 vid;
+    u16 pid;
+    u8 interface_index;
+    u8 sub_class;
+    u8 protocol;
 
-    unsigned short max_packet_size_rx;
-    unsigned short max_packet_size_tx;
+    u16 max_packet_size_rx;
+    u16 max_packet_size_tx;
 
 } HIDDevice;
 
@@ -58,7 +60,7 @@ struct _HIDClient
     HIDAttachCallback attach_cb;
 };
 
-typedef void (*HIDCallback)(u32 handle,s32 error,unsigned char *p_buffer,u32 bytes_transferred,void *p_user);
+typedef void (*HIDCallback)(u32 handle,s32 error,u8 *p_buffer,u32 bytes_transferred,void *p_user);
 
 void InitSysHIDFunctionPointers(void);
 void InitAcquireSysHID(void);
@@ -69,8 +71,8 @@ extern s32(*HIDTeardown)(void);
 extern s32(*HIDAddClient)(HIDClient *p_client, HIDAttachCallback attach_callback);
 extern s32(*HIDDelClient)(HIDClient *p_client);
 
-extern s32(*HIDGetDescriptor)(u32 handle,u8 descriptor_type,u8 descriptor_index, u16 language_id, unsigned char *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
-extern s32(*HIDSetDescriptor)(u32 handle,u8 descriptor_type,u8 descriptor_index, u16 language_id, unsigned char *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
+extern s32(*HIDGetDescriptor)(u32 handle,u8 descriptor_type,u8 descriptor_index, u16 language_id, u8 *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
+extern s32(*HIDSetDescriptor)(u32 handle,u8 descriptor_type,u8 descriptor_index, u16 language_id, u8 *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
 
 extern s32(*HIDGetReport)(u32 handle, u8 report_type, u8 report_id, u8 *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
 extern s32(*HIDSetReport)(u32 handle, u8 report_type, u8 report_id, u8 *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
@@ -80,8 +82,8 @@ extern s32(*HIDSetIdle)(u32 handle, u8 s32erface_index,u8 duration, HIDCallback
 extern s32(* HIDSetProtocol)(u32 handle,u8 s32erface_index,u8 protocol, HIDCallback hc, void *p_user);
 extern s32(* HIDGetProtocol)(u32 handle,u8 s32erface_index,u8 * protocol, HIDCallback hc, void *p_user);
 
-extern s32(*HIDRead)(u32 handle, unsigned char *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
-extern s32(*HIDWrite)(u32 handle, unsigned char *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
+extern s32(*HIDRead)(u32 handle, u8 *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
+extern s32(*HIDWrite)(u32 handle, u8 *p_buffer, u32 buffer_length, HIDCallback hc, void *p_user);
 
 #ifdef __cplusplus
 }