diff --git a/gdb/coredep.c b/gdb/coredep.c
index 81fb3a42d50..6eec85a1075 100644
--- a/gdb/coredep.c
+++ b/gdb/coredep.c
@@ -25,9 +25,8 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #include "gdbcore.h"
 #include <stdio.h>
 
-/* Some of these are needed on various systems, perhaps, to expand
-   REGISTER_U_ADDR appropriately?  */
-/* #include <sys/core.h> */
+/* These are needed on various systems to expand REGISTER_U_ADDR.  */
+#include <sys/types.h>
 #include <sys/param.h>
 #include <sys/dir.h>
 #include <sys/file.h>
diff --git a/gdb/xm-mips.h b/gdb/xm-mips.h
index 29d523e4823..4b5eb5fd8d7 100644
--- a/gdb/xm-mips.h
+++ b/gdb/xm-mips.h
@@ -23,18 +23,18 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 #define HOST_BYTE_ORDER LITTLE_ENDIAN
 #endif
 
-/* wait.h */
-#define HAVE_WAIT_STRUCT
-
 /* Get rid of any system-imposed stack limit if possible */
 
 #define	SET_STACK_LIMIT_HUGE
 
 /* This WOULD BE the amount to subtract from u.u_ar0
    to get the offset in the core file of the register values.
-   But Mips' ptrace works on regnums, not displacements */
+   But Mips' ptrace works on regnums, not displacements.  So since
+   REGISTER_U_ADDR is called for both core files and ptrace, use
+   BLOCKEND as a flag:  0 for core files, 1 for ptrace.  What a
+   kludge.  */
 
-#define KERNEL_U_ADDR (int)u.u_ar0
+#define KERNEL_U_ADDR (int)reg_ptr	/* Magic, causes a zero blockend */
 
 #define REGISTER_U_ADDR(addr, blockend, regno) 		\
    if (blockend == 0) {					\
@@ -55,7 +55,3 @@ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
 
 /* Kernel is a bit tenacious about sharing text segments, disallowing bpts.  */
 #define	ONE_PROCESS_WRITETEXT
-
-/* Interface definitions for kernel debugger KDB */
-
-/* I am not going to pretend I've done anything about this */