diff --git a/include/uapi/linux/auto_fs.h b/include/uapi/linux/auto_fs.h
index 77cdba9df27..bb991dfe134 100644
--- a/include/uapi/linux/auto_fs.h
+++ b/include/uapi/linux/auto_fs.h
@@ -28,25 +28,16 @@
 #define AUTOFS_MIN_PROTO_VERSION	AUTOFS_PROTO_VERSION
 
 /*
- * Architectures where both 32- and 64-bit binaries can be executed
- * on 64-bit kernels need this.  This keeps the structure format
- * uniform, and makes sure the wait_queue_token isn't too big to be
- * passed back down to the kernel.
- *
- * This assumes that on these architectures:
- * mode     32 bit    64 bit
- * -------------------------
- * int      32 bit    32 bit
- * long     32 bit    64 bit
- *
- * If so, 32-bit user-space code should be backwards compatible.
+ * The wait_queue_token (autofs_wqt_t) is part of a structure which is passed
+ * back to the kernel via ioctl from userspace. On architectures where 32- and
+ * 64-bit userspace binaries can be executed it's important that the size of
+ * autofs_wqt_t stays constant between 32- and 64-bit Linux kernels so that we
+ * do not break the binary ABI interface by changing the structure size.
  */
-
-#if defined(__sparc__) || defined(__mips__) || defined(__x86_64__) \
- || defined(__powerpc__) || defined(__s390__)
-typedef unsigned int autofs_wqt_t;
-#else
+#if defined(__ia64__) || defined(__alpha__) /* pure 64bit architectures */
 typedef unsigned long autofs_wqt_t;
+#else
+typedef unsigned int autofs_wqt_t;
 #endif
 
 /* Packet types */