diff --git a/debug.c b/debug.c
index 1bcd095901..3ec7da4c05 100644
--- a/debug.c
+++ b/debug.c
@@ -13,12 +13,14 @@
 #include "ruby/encoding.h"
 #include "ruby/util.h"
 #include "debug.h"
+#include "eval_intern.h"
 #include "vm_core.h"
 
 /* for gdb */
 static const union {
     enum ruby_special_consts    special_consts;
     enum ruby_value_type        value_type;
+    enum ruby_tag_type          tag_type;
     enum node_type              node_type;
     enum {
         RUBY_ENCODING_INLINE_MAX = ENCODING_INLINE_MAX,
diff --git a/eval_intern.h b/eval_intern.h
index c04befba58..c53cc32330 100644
--- a/eval_intern.h
+++ b/eval_intern.h
@@ -151,15 +151,26 @@ int _setjmp(), _longjmp();
 
 #define JUMP_TAG(st) TH_JUMP_TAG(GET_THREAD(), st)
 
-#define TAG_RETURN	0x1
-#define TAG_BREAK	0x2
-#define TAG_NEXT	0x3
-#define TAG_RETRY	0x4
-#define TAG_REDO	0x5
-#define TAG_RAISE	0x6
-#define TAG_THROW	0x7
-#define TAG_FATAL	0x8
-#define TAG_MASK	0xf
+enum ruby_tag_type {
+    RUBY_TAG_RETURN	= 0x1,
+    RUBY_TAG_BREAK	= 0x2,
+    RUBY_TAG_NEXT	= 0x3,
+    RUBY_TAG_RETRY	= 0x4,
+    RUBY_TAG_REDO	= 0x5,
+    RUBY_TAG_RAISE	= 0x6,
+    RUBY_TAG_THROW	= 0x7,
+    RUBY_TAG_FATAL	= 0x8,
+    RUBY_TAG_MASK	= 0xf
+};
+#define TAG_RETURN	RUBY_TAG_RETURN
+#define TAG_BREAK	RUBY_TAG_BREAK
+#define TAG_NEXT	RUBY_TAG_NEXT
+#define TAG_RETRY	RUBY_TAG_RETRY
+#define TAG_REDO	RUBY_TAG_REDO
+#define TAG_RAISE	RUBY_TAG_RAISE
+#define TAG_THROW	RUBY_TAG_THROW
+#define TAG_FATAL	RUBY_TAG_FATAL
+#define TAG_MASK	RUBY_TAG_MASK
 
 #define NEW_THROW_OBJECT(val, pt, st) \
   ((VALUE)NEW_NODE(NODE_LIT, (val), (pt), (st)))