diff --git a/include/apple2.h b/include/apple2.h
index d856c2840..eefd1a033 100644
--- a/include/apple2.h
+++ b/include/apple2.h
@@ -149,9 +149,9 @@ unsigned char get_ostype (void);
 void rebootafterexit (void);
 /* Reboot machine after program termination has completed. */
 
-unsigned char __fastcall__ rootdir (unsigned char drive, char* buf);
-/* Fill buffer with root directory name of ProDOS 8 disk in ProDOS 8 drive.
- * Returns 0 for success and an OS specific error code in case of failure.
+int __fastcall__ rootdir (unsigned char drive, char* buf);
+/* Fill buffer with root directory name of ProDOS 8 disk in
+ * ProDOS 8 drive. Returns 0 on success and -1 on error.
  */
 
 #define ser_apple2_slot(num)    ser_ioctl (0, (void*) (num))
diff --git a/libsrc/apple2/rootdir.s b/libsrc/apple2/rootdir.s
index baa4b445d..f3cf1f1ae 100644
--- a/libsrc/apple2/rootdir.s
+++ b/libsrc/apple2/rootdir.s
@@ -1,11 +1,11 @@
 ;
 ; Oliver Schmidt, 2010-05-24
 ;
-; unsigned char __fastcall__ rootdir (unsigned char drive, char* buf);
+; int __fastcall__ rootdir (unsigned char drive, char* buf);
 ;
 
         .export 	_rootdir
-        .import		popax
+        .import		popax, oserrexit
 
         .include	"zeropage.inc"
         .include	"errno.inc"
@@ -50,7 +50,5 @@ _rootdir:
         tax
         rts
         
-        ; Return error
-oserr:  sta	__oserror
-        ldx	#$00
-        rts
+        ; Return oserror
+oserr:  jmp	oserrexit