diff --git a/Lib/test/test_time.py b/Lib/test/test_time.py
index 2b58093f929..8499af81577 100644
--- a/Lib/test/test_time.py
+++ b/Lib/test/test_time.py
@@ -3,6 +3,7 @@ import time
 import unittest
 import locale
 import sysconfig
+import sys
 import warnings
 
 class TimeTestCase(unittest.TestCase):
@@ -39,6 +40,13 @@ class TimeTestCase(unittest.TestCase):
             except ValueError:
                 self.fail('conversion specifier: %r failed.' % format)
 
+        # Issue #10762: Guard against invalid/non-supported format string
+        # so that Python don't crash (Windows crashes when the format string
+        # input to [w]strftime is not kosher.
+        if sys.platform.startswith('win'):
+            with self.assertRaises(ValueError):
+                time.strftime('%f')
+
     def _bounds_checking(self, func=time.strftime):
         # Make sure that strftime() checks the bounds of the various parts
         #of the time tuple (0 is valid for *all* values).
diff --git a/Modules/timemodule.c b/Modules/timemodule.c
index c3b51efc5be..3af041a2b6f 100644
--- a/Modules/timemodule.c
+++ b/Modules/timemodule.c
@@ -512,7 +512,7 @@ time_strftime(PyObject *self, PyObject *args)
         if (outbuf[1]=='#')
             ++outbuf; /* not documented by python, */
         if (outbuf[1]=='\0' ||
-            !wcschr(L"aAbBcdfHIjmMpSUwWxXyYzZ%", outbuf[1]))
+            !wcschr(L"aAbBcdHIjmMpSUwWxXyYzZ%", outbuf[1]))
         {
             PyErr_SetString(PyExc_ValueError, "Invalid format string");
             return 0;