diff --git a/src/nu/nucontpakfilereadwrite.c b/src/nu/nucontpakfilereadwrite.c
index 4e9723f..71e8210 100644
--- a/src/nu/nucontpakfilereadwrite.c
+++ b/src/nu/nucontpakfilereadwrite.c
@@ -1,3 +1,18 @@
 #include "common.h"
 
-INCLUDE_ASM(const s32, "nu/nucontpakfilereadwrite", nuContPakFileReadWrite);
+#include "nu/nusys.h"
+
+/* 1B290 8008AE90 */
+s32 nuContPakFileReadWrite(NUContPakFile* file, s32 offset, s32 size, u8* buf, u32 mode) {
+    NUContPakFileRWMesg mesg;
+
+    mesg.file = file;
+    mesg.offset = offset;
+    mesg.size = size;
+    mesg.mode = mode;
+    mesg.buf = buf;
+    
+    file->error = nuSiSendMesg(NU_CONT_PAK_READWRITE_MSG, &mesg);
+    return file->error;
+}
+