diff --git a/edx_when/__init__.py b/edx_when/__init__.py
index 891e777..a855068 100644
--- a/edx_when/__init__.py
+++ b/edx_when/__init__.py
@@ -4,6 +4,6 @@
 
 from __future__ import absolute_import, unicode_literals
 
-__version__ = '0.3'
+__version__ = '0.4'
 
 default_app_config = 'edx_when.apps.EdxWhenConfig'  # pylint: disable=invalid-name
diff --git a/edx_when/api.py b/edx_when/api.py
index 1adc450..0a2ab00 100644
--- a/edx_when/api.py
+++ b/edx_when/api.py
@@ -74,7 +74,7 @@ def get_dates_for_course(course_id, user=None, use_cached=True):
     """
     log.debug("Getting dates for %s as %s", course_id, user)
 
-    cache_key = 'course_dates.%s'
+    cache_key = 'course_dates.%s' % course_id
     if user:
         if isinstance(user, int):
             user_id = user
diff --git a/test_utils/__init__.py b/test_utils/__init__.py
index 6c4fea0..be8f2a4 100644
--- a/test_utils/__init__.py
+++ b/test_utils/__init__.py
@@ -19,14 +19,14 @@ def make_block_id(course_id='testX+tt101+2019', block_type='sequential+block'):
     return UsageKey.from_string(block_id)
 
 
-def make_items():
+def make_items(course_id='testX+tt101+2019'):
     """
     Return item list for set_dates_for_course.
     """
     items = [
-        (make_block_id(), {'due': datetime(2019, 3, 22)}),
-        (make_block_id(), {'due': datetime(2019, 3, 23), 'test': '1'}),
-        (make_block_id(), {'start': datetime(2019, 3, 21), 'test': '1'}),
-        (make_block_id(), {'start': None, 'test': '1'}),
+        (make_block_id(course_id), {'due': datetime(2019, 3, 22)}),
+        (make_block_id(course_id), {'due': datetime(2019, 3, 23), 'test': '1'}),
+        (make_block_id(course_id), {'start': datetime(2019, 3, 21), 'test': '1'}),
+        (make_block_id(course_id), {'start': None, 'test': '1'}),
     ]
     return items
diff --git a/tests/test_api.py b/tests/test_api.py
index 2e5629f..4abd888 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -42,6 +42,15 @@ def test_get_dates_for_course(self):
         # second time is cached
         retrieved = api.get_dates_for_course(items[0][0].course_key)
         assert len(retrieved) == 3
+
+        # third time with new course_id
+        new_items = make_items('testX+tt202+2019')
+        api.set_dates_for_course(new_items[0][0].course_key, new_items)
+        new_retrieved = api.get_dates_for_course(new_items[0][0].course_key)
+        assert len(new_retrieved) == 3
+        first_id = list(new_retrieved.keys())[0][0]
+        last_id = list(retrieved.keys())[0][0]
+        assert first_id.course_key != last_id.course_key
         return items
 
     def test_clear_dates_for_course(self):