diff --git a/src/.gdbinit b/src/.gdbinit
index 25b555b85400b09307ee09265db6f1996886bf5e..620ca63a0d6bf24f8ee6beb911e30e70a54d0a79 100644
--- a/src/.gdbinit
+++ b/src/.gdbinit
@@ -653,7 +653,11 @@ end
 define xvectype
   xgetptr $
   set $size = ((struct Lisp_Vector *) $ptr)->header.size
-  output ($size & PSEUDOVECTOR_FLAG) ? (enum pvec_type) ($size & PVEC_TYPE_MASK) : $size & ~ARRAY_MARK_FLAG
+  if ($size & PSEUDOVECTOR_FLAG)
+    output (enum pvec_type) (($size & PVEC_TYPE_MASK) >> PSEUDOVECTOR_SIZE_BITS)
+  else
+    output $size & ~ARRAY_MARK_FLAG
+  end
   echo \n
 end
 document xvectype
@@ -992,7 +996,7 @@ define xpr
   if $type == Lisp_Vectorlike
     set $size = ((struct Lisp_Vector *) $ptr)->header.size
     if ($size & PSEUDOVECTOR_FLAG)
-      set $vec = (enum pvec_type) ($size & PVEC_TYPE_MASK)
+      set $vec = (enum pvec_type) (($size & PVEC_TYPE_MASK) >> PSEUDOVECTOR_SIZE_BITS)
       if $vec == PVEC_NORMAL_VECTOR
 	xvector
       end
@@ -1127,7 +1131,11 @@ define xbacktrace
       if $type == Lisp_Vectorlike
 	xgetptr (*$bt->function)
         set $size = ((struct Lisp_Vector *) $ptr)->header.size
-        output ($size & PSEUDOVECTOR_FLAG) ? (enum pvec_type) ($size & PVEC_TYPE_MASK) : $size & ~ARRAY_MARK_FLAG
+        if ($size & PSEUDOVECTOR_FLAG)
+	  output (enum pvec_type) (($size & PVEC_TYPE_MASK) >> PSEUDOVECTOR_SIZE_BITS)
+	else
+	  output $size & ~ARRAY_MARK_FLAG
+	end
       else
         printf "Lisp type %d", $type
       end
diff --git a/src/ChangeLog b/src/ChangeLog
index 392e25398dbbbfe78edb45f4dfada29625f168b6..42b92de5c26694af1fa916e01ad35af9e1e3d073 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,10 @@
+2012-07-27  Paul Eggert  <eggert@cs.ucla.edu>
+
+	Adjust GDB to reflect pvec_type changes (Bug#12036).
+	* .gdbinit (xvectype, xpr, xbacktrace): Adjust to reflect the
+	2012-07-04 changes to pseudovector representation.  Problem
+	reported by Eli Zaretskii in <http://bugs.gnu.org/12036#30>.
+
 2012-07-27  Michael Albinus  <michael.albinus@gmx.de>
 
 	* dbusbind.c (XD_DBUS_VALIDATE_BUS_ADDRESS): Canonicalize session