diff --git a/moto/cloudformation/parsing.py b/moto/cloudformation/parsing.py
index 6b655983..c4059a06 100644
--- a/moto/cloudformation/parsing.py
+++ b/moto/cloudformation/parsing.py
@@ -252,6 +252,10 @@ def generate_resource_name(resource_type, stack_name, logical_id):
         name_prefix = '{0}-{1}'.format(stack_name, logical_id)
         my_random_suffix = random_suffix()
         truncated_name_prefix = name_prefix[0:32 - (len(my_random_suffix) + 1)]
+        # if the truncated name ends in a dash, we'll end up with a double dash in the final name, which is
+        # not allowed
+        if truncated_name_prefix.endswith('-'):
+            truncated_name_prefix = truncated_name_prefix[:-1]
         return '{0}-{1}'.format(truncated_name_prefix, my_random_suffix)
     else:
         return '{0}-{1}-{2}'.format(stack_name, logical_id, random_suffix())
diff --git a/tests/test_elbv2/test_elbv2.py b/tests/test_elbv2/test_elbv2.py
index c5c42538..b58345fd 100644
--- a/tests/test_elbv2/test_elbv2.py
+++ b/tests/test_elbv2/test_elbv2.py
@@ -1584,5 +1584,5 @@ def test_create_target_groups_through_cloudformation():
     # and one named MyTargetGroup
     assert len([tg for tg in target_group_dicts if tg['TargetGroupName'] == 'MyTargetGroup']) == 1
     assert len(
-        [tg for tg in target_group_dicts if tg['TargetGroupName'].startswith('test-stack-test')]
+        [tg for tg in target_group_dicts if tg['TargetGroupName'].startswith('test-stack')]
     ) == 2