diff -r b6ca2d734f8e Lib/subprocess.py
--- a/Lib/subprocess.py	Wed Sep 14 23:54:09 2016 -0700
+++ b/Lib/subprocess.py	Fri Sep 16 23:46:08 2016 +0000
@@ -1296,8 +1296,8 @@
             else:
                 timeout_millis = int(timeout * 1000)
             if self.returncode is None:
-                result = _winapi.WaitForSingleObject(self._handle,
-                                                    timeout_millis)
+                result = _winapi.WaitForMultipleObjects(
+                            [self._handle], False, timeout_millis)
                 if result == _winapi.WAIT_TIMEOUT:
                     raise TimeoutExpired(self.args, timeout)
                 self.returncode = _winapi.GetExitCodeProcess(self._handle)
diff -r b6ca2d734f8e Modules/_winapi.c
--- a/Modules/_winapi.c	Wed Sep 14 23:54:09 2016 -0700
+++ b/Modules/_winapi.c	Fri Sep 16 23:46:08 2016 +0000
@@ -1322,6 +1322,7 @@
     HANDLE handles[MAXIMUM_WAIT_OBJECTS];
     HANDLE sigint_event = NULL;
     Py_ssize_t nhandles, i;
+    ULONGLONG deadline = GetTickCount64() + milliseconds;
 
     if (!PySequence_Check(handle_seq)) {
         PyErr_Format(PyExc_TypeError,
@@ -1358,21 +1359,41 @@
         handles[nhandles++] = sigint_event;
     }
 
-    Py_BEGIN_ALLOW_THREADS
-    if (sigint_event != NULL)
-        ResetEvent(sigint_event);
-    result = WaitForMultipleObjects((DWORD) nhandles, handles,
-                                    wait_flag, milliseconds);
-    Py_END_ALLOW_THREADS
+    do {
+        LONGLONG remaining;
+
+        Py_BEGIN_ALLOW_THREADS
+        if (sigint_event)
+            ResetEvent(sigint_event);
+        result = WaitForMultipleObjects((DWORD)nhandles, handles,
+                                        wait_flag, milliseconds);
+        Py_END_ALLOW_THREADS
+
+        if (!sigint_event ||
+            result != WAIT_OBJECT_0 + nhandles - 1)
+            break;
+
+        if (PyErr_CheckSignals())
+            return NULL;
+
+        if (milliseconds != INFINITE) {
+            remaining = deadline - GetTickCount64();
+            
+            if (remaining < 0) {
+                if (nhandles > 1) /* wait 0 ms, without sigint_event */
+                    result = WaitForMultipleObjects((DWORD)(nhandles - 1),
+                                                    handles, wait_flag, 0);
+                else /* Don't return an implicit WAIT_OBJECT_0 */
+                    result = WAIT_TIMEOUT;
+                break;
+            }
+            milliseconds = (DWORD)remaining;
+        }
+    } while (1);
 
     if (result == WAIT_FAILED)
         return PyErr_SetExcFromWindowsErr(PyExc_IOError, 0);
-    else if (sigint_event != NULL && result == WAIT_OBJECT_0 + nhandles - 1) {
-        errno = EINTR;
-        return PyErr_SetFromErrno(PyExc_IOError);
-    }
-
-    return PyLong_FromLong((int) result);
+    return PyLong_FromLong((int)result);
 }
 
 /*[clinic input]