diff --git a/.gdbinit b/.gdbinit
index 9127db09ef..6fe7b32cfd 100644
--- a/.gdbinit
+++ b/.gdbinit
@@ -316,6 +316,36 @@ define rp_id
   if $id == idASET
     printf "(:[]=)\n"
   else
+    if $id <= tLAST_OP_ID
+      printf "O"
+    else
+      set $id_type = $id & RUBY_ID_SCOPE_MASK
+      if $id_type == RUBY_ID_LOCAL
+        printf "l"
+      else
+      if $id_type == RUBY_ID_INSTANCE
+        printf "i"
+      else
+      if $id_type == RUBY_ID_GLOBAL
+        printf "G"
+      else
+      if $id_type == RUBY_ID_ATTRSET
+        printf "a"
+      else
+      if $id_type == RUBY_ID_CONST
+        printf "C"
+      else
+      if $id_type == RUBY_ID_CLASS
+        printf "c"
+      else
+        printf "j"
+      end
+      end
+      end
+      end
+      end
+      end
+    end
     printf "(%ld): ", $id
     rb_numtable_entry global_symbols.id_str $id
     if $rb_numtable_rec
diff --git a/debug.c b/debug.c
index 7cd166495f..be70dafec3 100644
--- a/debug.c
+++ b/debug.c
@@ -24,6 +24,7 @@ const union {
     enum ruby_tag_type          tag_type;
     enum node_type              node_type;
     enum ruby_method_ids        method_ids;
+    enum ruby_id_types          id_types;
     enum {
         RUBY_ENCODING_INLINE_MAX = ENCODING_INLINE_MAX,
         RUBY_ENCODING_SHIFT = ENCODING_SHIFT,
diff --git a/template/id.h.tmpl b/template/id.h.tmpl
index c993243424..9df7947214 100644
--- a/template/id.h.tmpl
+++ b/template/id.h.tmpl
@@ -28,16 +28,29 @@ types = ids.keys.grep(/^[A-Z]/)
 #ifndef RUBY_ID_H
 #define RUBY_ID_H
 
-#define ID_SCOPE_SHIFT 3
-#define ID_SCOPE_MASK 0x07
-#define ID_LOCAL      0x00
-#define ID_INSTANCE   0x01
-#define ID_GLOBAL     0x03
-#define ID_ATTRSET    0x04
-#define ID_CONST      0x05
-#define ID_CLASS      0x06
-#define ID_JUNK       0x07
-#define ID_INTERNAL   ID_JUNK
+enum ruby_id_types {
+    RUBY_ID_LOCAL       = 0x00,
+    RUBY_ID_INSTANCE    = 0x01,
+    RUBY_ID_GLOBAL      = 0x03,
+    RUBY_ID_ATTRSET     = 0x04,
+    RUBY_ID_CONST       = 0x05,
+    RUBY_ID_CLASS       = 0x06,
+    RUBY_ID_JUNK        = 0x07,
+    RUBY_ID_INTERNAL    = RUBY_ID_JUNK,
+    RUBY_ID_SCOPE_SHIFT = 3,
+    RUBY_ID_SCOPE_MASK  = ~(~0U<<RUBY_ID_SCOPE_SHIFT)
+};
+
+#define ID_SCOPE_SHIFT RUBY_ID_SCOPE_SHIFT
+#define ID_SCOPE_MASK  RUBY_ID_SCOPE_MASK
+#define ID_LOCAL       RUBY_ID_LOCAL
+#define ID_INSTANCE    RUBY_ID_INSTANCE
+#define ID_GLOBAL      RUBY_ID_GLOBAL
+#define ID_ATTRSET     RUBY_ID_ATTRSET
+#define ID_CONST       RUBY_ID_CONST
+#define ID_CLASS       RUBY_ID_CLASS
+#define ID_JUNK        RUBY_ID_JUNK
+#define ID_INTERNAL    RUBY_ID_INTERNAL
 
 #define ID2ATTRSET(id) (((id)&~ID_SCOPE_MASK)|ID_ATTRSET)