Do not pollute name block_ty, prefix with _Py_
diff --git a/Include/symtable.h b/Include/symtable.h
index ad7334b..d1e7b35 100644
--- a/Include/symtable.h
+++ b/Include/symtable.h
@@ -5,7 +5,7 @@
 #endif
 
 typedef enum _block_type { FunctionBlock, ClassBlock, ModuleBlock }
-    block_ty;
+    _Py_block_ty;
 
 struct _symtable_entry;
 
@@ -29,7 +29,7 @@
 	PyObject *ste_name;      /* string: name of block */
 	PyObject *ste_varnames;  /* list of variable names */
 	PyObject *ste_children;  /* list of child ids */
-	block_ty ste_type;       /* module, class, or function */
+	_Py_block_ty ste_type;   /* module, class, or function */
 	int ste_unoptimized;     /* false if namespace is optimized */
 	int ste_nested : 1;      /* true if block is nested */
 	int ste_free : 1;        /* true if block has free variables */
@@ -49,7 +49,7 @@
 #define PySTEntry_Check(op) ((op)->ob_type == &PySTEntry_Type)
 
 PyAPI_FUNC(PySTEntryObject *) \
-	PySTEntry_New(struct symtable *, identifier, block_ty, void *, int);
+	PySTEntry_New(struct symtable *, identifier, _Py_block_ty, void *, int);
 PyAPI_FUNC(int) PyST_GetScope(PySTEntryObject *, PyObject *);
 
 PyAPI_FUNC(struct symtable *) PySymtable_Build(mod_ty, const char *, 
diff --git a/Python/symtable.c b/Python/symtable.c
index 46efe4b..28da563 100644
--- a/Python/symtable.c
+++ b/Python/symtable.c
@@ -12,7 +12,7 @@
 "name '%.400s' is used prior to global declaration"
 
 PySTEntryObject *
-PySTEntry_New(struct symtable *st, identifier name, block_ty block,
+PySTEntry_New(struct symtable *st, identifier name, _Py_block_ty block,
 	      void *key, int lineno)
 {
 	PySTEntryObject *ste = NULL;
@@ -153,7 +153,7 @@
 static int symtable_analyze(struct symtable *st);
 static int symtable_warn(struct symtable *st, char *msg);
 static int symtable_enter_block(struct symtable *st, identifier name, 
-				block_ty block, void *ast, int lineno);
+				_Py_block_ty block, void *ast, int lineno);
 static int symtable_exit_block(struct symtable *st, void *ast);
 static int symtable_visit_stmt(struct symtable *st, stmt_ty s);
 static int symtable_visit_expr(struct symtable *st, expr_ty s);
@@ -711,7 +711,7 @@
 }
 
 static int
-symtable_enter_block(struct symtable *st, identifier name, block_ty block, 
+symtable_enter_block(struct symtable *st, identifier name, _Py_block_ty block, 
 		     void *ast, int lineno)
 {
 	PySTEntryObject *prev = NULL;