diff --git a/Lib/test/test_bool.py b/Lib/test/test_bool.py
index 7a9022e..bbaea85 100644
--- a/Lib/test/test_bool.py
+++ b/Lib/test/test_bool.py
@@ -163,6 +163,12 @@
         self.assertIs(bool(""), False)
         self.assertIs(bool(), False)
 
+    def test_format(self):
+        self.assertEqual("%d" % False, "0")
+        self.assertEqual("%d" % True, "1")
+        self.assertEqual("%x" % False, "0")
+        self.assertEqual("%x" % True, "1")
+
     def test_hasattr(self):
         self.assertIs(hasattr([], "append"), True)
         self.assertIs(hasattr([], "wobble"), False)
diff --git a/Objects/stringobject.c b/Objects/stringobject.c
index 7a35974..b1d711d 100644
--- a/Objects/stringobject.c
+++ b/Objects/stringobject.c
@@ -4144,11 +4144,14 @@
 		return NULL;
 	}
 
-
 	switch (type) {
 	case 'd':
 	case 'u':
-		result = Py_Type(val)->tp_str(val);
+		/* Special-case boolean: we want 0/1 */
+		if (PyBool_Check(val))
+			result = PyNumber_ToBase(val, 10);
+		else
+			result = Py_Type(val)->tp_str(val);
 		break;
 	case 'o':
 		numnondigits = 2;