diff --git a/Lib/test/test_ast.py b/Lib/test/test_ast.py
index 04e8308ef12..77839c20381 100644
--- a/Lib/test/test_ast.py
+++ b/Lib/test/test_ast.py
@@ -367,6 +367,20 @@ class AST_Tests(unittest.TestCase):
             compile(m, "<test>", "exec")
         self.assertIn("but got <_ast.expr", str(cm.exception))
 
+    def test_invalid_identitifer(self):
+        m = ast.Module([ast.Expr(ast.Name(42, ast.Load()))])
+        ast.fix_missing_locations(m)
+        with self.assertRaises(TypeError) as cm:
+            compile(m, "<test>", "exec")
+        self.assertIn("identifier must be of type str", str(cm.exception))
+
+    def test_invalid_string(self):
+        m = ast.Module([ast.Expr(ast.Str(42))])
+        ast.fix_missing_locations(m)
+        with self.assertRaises(TypeError) as cm:
+            compile(m, "<test>", "exec")
+        self.assertIn("string must be of type str", str(cm.exception))
+
 
 class ASTHelpers_Test(unittest.TestCase):
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 7bccc05fc63..281a9e3e425 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,9 @@ What's New in Python 3.3 Alpha 1?
 Core and Builtins
 -----------------
 
+- Verify the types of AST strings and identifiers provided by the user before
+  compiling them.
+
 - Issue #12579: str.format_map() now raises a ValueError if used on a
   format string that contains positional fields. Initial patch by
   Julian Berman.
diff --git a/Parser/asdl_c.py b/Parser/asdl_c.py
index 22ef3d0af1b..c38a8533f71 100755
--- a/Parser/asdl_c.py
+++ b/Parser/asdl_c.py
@@ -795,8 +795,25 @@ static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
     return 0;
 }
 
-#define obj2ast_identifier obj2ast_object
-#define obj2ast_string obj2ast_object
+static int obj2ast_stringlike(PyObject* obj, PyObject** out, PyArena* arena,
+    const char *name)
+{
+    if (!PyUnicode_CheckExact(name)) {
+        PyErr_Format(PyExc_TypeError, "AST %s must be of type str", name);
+        return 1;
+    }
+    return obj2ast_object(obj, out, arena);
+}
+
+static int obj2ast_identifier(PyObject* obj, PyObject** out, PyArena* arena)
+{
+    return obj2ast_stringlike(obj, out, arena, "identifier");
+}
+
+static int obj2ast_string(PyObject* obj, PyObject** out, PyArena* arena)
+{
+    return obj2ast_stringlike(obj, out, arena, "string");
+}
 
 static int obj2ast_int(PyObject* obj, int* out, PyArena* arena)
 {
diff --git a/Python/Python-ast.c b/Python/Python-ast.c
index 96c6bf83fc7..a1866470d56 100644
--- a/Python/Python-ast.c
+++ b/Python/Python-ast.c
@@ -592,8 +592,25 @@ static int obj2ast_object(PyObject* obj, PyObject** out, PyArena* arena)
     return 0;
 }
 
-#define obj2ast_identifier obj2ast_object
-#define obj2ast_string obj2ast_object
+static int obj2ast_stringlike(PyObject* obj, PyObject** out, PyArena* arena,
+    const char *name)
+{
+    if (!PyUnicode_CheckExact(name)) {
+        PyErr_Format(PyExc_TypeError, "AST %s must be of type str", name);
+        return 1;
+    }
+    return obj2ast_object(obj, out, arena);
+}
+
+static int obj2ast_identifier(PyObject* obj, PyObject** out, PyArena* arena)
+{
+    return obj2ast_stringlike(obj, out, arena, "identifier");
+}
+
+static int obj2ast_string(PyObject* obj, PyObject** out, PyArena* arena)
+{
+    return obj2ast_stringlike(obj, out, arena, "string");
+}
 
 static int obj2ast_int(PyObject* obj, int* out, PyArena* arena)
 {