diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 56b5ffa..35eae1e 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -166,6 +166,8 @@
         sio = StringIO(self.TEXT)
         bz2f.writelines(sio.readlines())
         bz2f.close()
+        # patch #1535500
+        self.assertRaises(ValueError, bz2f.writelines, ["a"])
         f = open(self.filename, 'rb')
         self.assertEqual(self.decompress(f.read()), self.TEXT)
         f.close()
diff --git a/Misc/NEWS b/Misc/NEWS
index 2d1a5e4..06dde4a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -79,6 +79,9 @@
 Extension Modules
 -----------------
 
+- Patch #1535500: fix segfault in BZ2File.writelines and make sure it
+  raises the correct exceptions.
+
 - Patch # 1536908: enable building ctypes on OpenBSD/AMD64.  The
   '-no-stack-protector' compiler flag for OpenBSD has been removed.
 
diff --git a/Modules/bz2module.c b/Modules/bz2module.c
index 5e5a801..24b2489 100644
--- a/Modules/bz2module.c
+++ b/Modules/bz2module.c
@@ -812,12 +812,12 @@
 		case MODE_CLOSED:
 			PyErr_SetString(PyExc_ValueError,
 					"I/O operation on closed file");
-			goto cleanup;;
+			goto cleanup;
 
 		default:
 			PyErr_SetString(PyExc_IOError,
 					"file is not ready for writing");
-			goto cleanup;;
+			goto cleanup;
 	}
 
 	self->f_softspace = 0;
@@ -861,6 +861,21 @@
 	int bzerror;
 
 	ACQUIRE_LOCK(self);
+	switch (self->mode) {
+		case MODE_WRITE:
+			break;
+
+		case MODE_CLOSED:
+			PyErr_SetString(PyExc_ValueError,
+					"I/O operation on closed file");
+			goto error;
+
+		default:
+			PyErr_SetString(PyExc_IOError,
+					"file is not ready for writing");
+			goto error;
+	}
+
 	islist = PyList_Check(seq);
 	if  (!islist) {
 		iter = PyObject_GetIter(seq);