diff -r be1e015a8405 Lib/test/test_datetime_strptime.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Lib/test/test_datetime_strptime.py	Tue Mar 18 21:21:18 2014 +0100
@@ -0,0 +1,31 @@
+from test import test_support
+import unittest
+import threading
+
+from datetime import datetime
+
+class StressDateTimeStrptime(threading.Thread):
+    def run(self):
+        self.error_raised=False
+        try:
+            for m in range(1, 13):
+                for d in range(1,29):
+                    datetime.strptime("2010%02d%02d"%(m,d),"%Y%m%d")
+        except AttributeError:
+            self.error_raised=True
+
+class TestStrptimeAttributeInThread(unittest.TestCase):
+    def test_run_in_thread(self):
+        threads=[StressDateTimeStrptime() for _ in range(10)]
+        for t in threads:
+            t.start()
+        for t in threads:
+            t.join()
+            self.assertFalse(t.error_raised,
+                             'should not raise AttributeError for strptime')
+
+def test_main():
+    test_support.run_unittest(TestStrptimeAttributeInThread)
+
+if __name__ == "__main__":
+    test_main()
diff -r be1e015a8405 Lib/test/test_time_strptime.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Lib/test/test_time_strptime.py	Tue Mar 18 21:21:18 2014 +0100
@@ -0,0 +1,30 @@
+from test import test_support
+import time
+import unittest
+import threading
+
+class StressTimeStrptime(threading.Thread):
+    def run(self):
+        self.error_raised=False
+        try:
+            for m in range(1, 13):
+                for d in range(1,29):
+                    time.strptime("2010%02d%02d"%(m,d),"%Y%m%d")
+        except AttributeError:
+            self.error_raised=True
+
+class TestStrptimeAttributeInThread(unittest.TestCase):
+    def test_run_in_thread(self):
+        threads=[StressTimeStrptime() for _ in range(10)]
+        for t in threads:
+            t.start()
+        for t in threads:
+            t.join()
+            self.assertFalse(t.error_raised,
+                             'should not raise AttributeError for strptime')
+
+def test_main():
+    test_support.run_unittest(TestStrptimeAttributeInThread)
+
+if __name__ == "__main__":
+    test_main()
diff -r be1e015a8405 Modules/datetimemodule.c
--- a/Modules/datetimemodule.c	Tue Mar 18 09:18:53 2014 -0500
+++ b/Modules/datetimemodule.c	Tue Mar 18 21:21:18 2014 +0100
@@ -105,6 +105,9 @@
 static PyTypeObject PyDateTime_TimeType;
 static PyTypeObject PyDateTime_TZInfoType;
 
+/* Single reference to the _strptime module, set in module init method */
+static PyObject *strptime_module = NULL;
+
 /* ---------------------------------------------------------------------------
  * Math utilities.
  */
@@ -3928,21 +3931,17 @@
 static PyObject *
 datetime_strptime(PyObject *cls, PyObject *args)
 {
-    static PyObject *module = NULL;
     PyObject *result = NULL, *obj, *st = NULL, *frac = NULL;
     const char *string, *format;
 
     if (!PyArg_ParseTuple(args, "ss:strptime", &string, &format))
         return NULL;
 
-    if (module == NULL &&
-        (module = PyImport_ImportModuleNoBlock("_strptime")) == NULL)
-        return NULL;
-
     /* _strptime._strptime returns a two-element tuple.  The first
        element is a time.struct_time object.  The second is the
        microseconds (which are not defined for time.struct_time). */
-    obj = PyObject_CallMethod(module, "_strptime", "ss", string, format);
+    obj = PyObject_CallMethod(strptime_module, "_strptime", "ss", string,
+                              format);
     if (obj != NULL) {
         int i, good_timetuple = 1;
         long int ia[7];
@@ -4916,6 +4915,11 @@
     us_per_week = PyLong_FromDouble(604800000000.0);
     if (us_per_hour == NULL || us_per_day == NULL || us_per_week == NULL)
         return;
+
+    strptime_module = PyImport_ImportModuleNoBlock("_strptime");
+    if (strptime_module == NULL)
+        return;
+    Py_INCREF(strptime_module);
 }
 
 /* ---------------------------------------------------------------------------
diff -r be1e015a8405 Modules/timemodule.c
--- a/Modules/timemodule.c	Tue Mar 18 09:18:53 2014 -0500
+++ b/Modules/timemodule.c	Tue Mar 18 21:21:18 2014 +0100
@@ -98,6 +98,9 @@
 /* For Y2K check */
 static PyObject *moddict = NULL;
 
+/* Single reference to the _strptime module, set in module init method */
+static PyObject *strptime_module = NULL;
+
 /* Exposed in timefuncs.h. */
 time_t
 _PyTime_DoubleToTimet(double x)
@@ -540,11 +543,8 @@
 static PyObject *
 time_strptime(PyObject *self, PyObject *args)
 {
-    PyObject *strptime_module = PyImport_ImportModuleNoBlock("_strptime");
     PyObject *strptime_result;
 
-    if (!strptime_module)
-        return NULL;
     strptime_result = PyObject_CallMethod(strptime_module,
                                             "_strptime_time", "O", args);
     Py_DECREF(strptime_module);
@@ -885,6 +885,12 @@
     }
     Py_INCREF(&StructTimeType);
     PyModule_AddObject(m, "struct_time", (PyObject*) &StructTimeType);
+
+    strptime_module = PyImport_ImportModuleNoBlock("_strptime");
+    if (strptime_module == NULL)
+        return;
+    Py_INCREF(strptime_module);
+
     initialized = 1;
 }