diff --git a/Lib/subprocess.py b/Lib/subprocess.py
index 93635ee61f7e9ff..b97eb3a77e5b398 100644
--- a/Lib/subprocess.py
+++ b/Lib/subprocess.py
@@ -502,6 +502,7 @@ def list2cmdline(seq):
     result = []
     needquote = False
     for arg in seq:
+        arg = os.fspath(arg)
         bs_buf = []
 
         # Add a space to separate this argument from the others
diff --git a/Lib/test/test_subprocess.py b/Lib/test/test_subprocess.py
index 2a766d7c92ad822..5d4415ab7f5df0d 100644
--- a/Lib/test/test_subprocess.py
+++ b/Lib/test/test_subprocess.py
@@ -18,6 +18,7 @@
 import threading
 import gc
 import textwrap
+import pathlib
 from test.support import FakePath
 
 try:
@@ -118,6 +119,19 @@ def test_io_unbuffered_works(self):
             p.stderr.close()
             p.wait()
 
+    def test_pathlib_executable(self):
+        p = subprocess.Popen([pathlib.Path(sys.executable), "-c",
+                              "import sys; sys.exit(47)"])
+        p.wait()
+        self.assertEqual(p.returncode, 47)
+
+    def test_pathlib_argument(self):
+        path = pathlib.Path(sys.executable)
+        output = subprocess.check_output([path, "-c",
+                                         "import sys; sys.stdout.write(sys.argv[1])",
+                                          path])
+        self.assertEqual(output, os.fspath(path).encode())
+
     def test_call_seq(self):
         # call() function with sequence argument
         rc = subprocess.call([sys.executable, "-c",
diff --git a/Misc/NEWS.d/next/Library/2018-05-23-15-27-00.bpo-33617.dj349j.rst b/Misc/NEWS.d/next/Library/2018-05-23-15-27-00.bpo-33617.dj349j.rst
new file mode 100644
index 000000000000000..c707ced6223a2ce
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2018-05-23-15-27-00.bpo-33617.dj349j.rst
@@ -0,0 +1 @@
+Use os.fspath() on elements of sequences passed to subprocess.Popen() on Windows.
\ No newline at end of file