diff --git a/common/djangoapps/student/models.py b/common/djangoapps/student/models.py
index 8f1a467ddd29..86177ee39713 100644
--- a/common/djangoapps/student/models.py
+++ b/common/djangoapps/student/models.py
@@ -222,12 +222,13 @@ def anonymous_id_for_user(user, course_id, save='DEPRECATED'):
         # Rotation process of SECRET_KEY with respect to this
         # function: Rotate at will, since the hashes are stored and
         # will not change.
-        hasher = hashlib.md5()
+        # include the secret key as a salt, and to make the ids unique across different LMS installs.
+        hasher = hashlib.shake_128()
         hasher.update(settings.SECRET_KEY.encode('utf8'))
         hasher.update(text_type(user.id).encode('utf8'))
         if course_id:
             hasher.update(text_type(course_id).encode('utf-8'))
-        anonymous_user_id = hasher.hexdigest()
+        anonymous_user_id = hasher.hexdigest(16)  # pylint: disable=too-many-function-args
 
         try:
             AnonymousUserId.objects.create(
diff --git a/lms/djangoapps/courseware/tests/test_module_render.py b/lms/djangoapps/courseware/tests/test_module_render.py
index 04c646126941..ef01e42fa198 100644
--- a/lms/djangoapps/courseware/tests/test_module_render.py
+++ b/lms/djangoapps/courseware/tests/test_module_render.py
@@ -1991,7 +1991,7 @@ def test_per_student_anonymized_id(self, descriptor_class):
             self.assertEqual(
                 # This value is set by observation, so that later changes to the student
                 # id computation don't break old data
-                '5afe5d9bb03796557ee2614f5c9611fb',
+                'de619ab51c7f4e9c7216b4644c24f3b5',
                 self._get_anonymous_id(CourseKey.from_string(course_id), descriptor_class)
             )
 
@@ -2000,14 +2000,14 @@ def test_per_course_anonymized_id(self, descriptor_class):
         self.assertEqual(
             # This value is set by observation, so that later changes to the student
             # id computation don't break old data
-            'e3b0b940318df9c14be59acb08e78af5',
+            '0c706d119cad686d28067412b9178454',
             self._get_anonymous_id(CourseKey.from_string('MITx/6.00x/2012_Fall'), descriptor_class)
         )
 
         self.assertEqual(
             # This value is set by observation, so that later changes to the student
             # id computation don't break old data
-            'f82b5416c9f54b5ce33989511bb5ef2e',
+            'e9969c28c12c8efa6e987d6dbeedeb0b',
             self._get_anonymous_id(CourseKey.from_string('MITx/6.00x/2013_Spring'), descriptor_class)
         )