--- a/buildout.cfg	Mon Jun 11 16:13:37 2018 +0200
+++ b/buildout.cfg	Wed Jun 13 11:39:04 2018 +0200
@@ -96,4 +96,4 @@
 eggs = pyams_utils [test]
 
 [versions]
-pyams_utils = 0.1.15
+pyams_utils = 0.1.16

--- a/setup.py	Mon Jun 11 16:13:37 2018 +0200
+++ b/setup.py	Wed Jun 13 11:39:04 2018 +0200
@@ -25,7 +25,7 @@
 README = os.path.join(DOCS, 'README.txt')
 HISTORY = os.path.join(DOCS, 'HISTORY.txt')
 
-version = '0.1.15'
+version = '0.1.16'
 long_description = open(README).read() + '\n\n' + open(HISTORY).read()
 
 tests_require = [

--- a/src/pyams_utils/adapter.py	Mon Jun 11 16:13:37 2018 +0200
+++ b/src/pyams_utils/adapter.py	Wed Jun 13 11:39:04 2018 +0200
@@ -159,6 +159,8 @@
         else:
             adapter = annotations[key] = factory()
             if markers:
+                if not isinstance(markers, (list, tuple, set)):
+                    markers = {markers}
                 for marker in markers:
                     alsoProvides(adapter, marker)
             if notify: