diff --git a/cli/koji_cli/commands.py b/cli/koji_cli/commands.py
index b8a77def..a4d19607 100644
--- a/cli/koji_cli/commands.py
+++ b/cli/koji_cli/commands.py
@@ -195,7 +195,7 @@ def handle_edit_host(options, session, args):
         if val is not None:
             vals[key] = val
     if 'arches' in vals:
-        vals['arches'] = parse_arches(vals['arches'])
+        vals['arches'] = koji.parse_arches(vals['arches'])
 
     session.multicall = True
     for host in args:
@@ -350,7 +350,7 @@ def handle_add_pkg(goptions, session, args):
             continue
         to_add.append(package)
     if options.extra_arches:
-        opts['extra_arches'] = parse_arches(options.extra_arches)
+        opts['extra_arches'] = koji.parse_arches(options.extra_arches)
 
     # add the packages
     print("Adding %i packages to tag %s" % (len(to_add), dsttag['name']))
@@ -477,7 +477,7 @@ def handle_build(options, session, args):
     source = args[1]
     opts = {}
     if build_opts.arch_override:
-        opts['arch_override'] = parse_arches(build_opts.arch_override)
+        opts['arch_override'] = koji.parse_arches(build_opts.arch_override)
     for key in ('skip_tag', 'scratch', 'repo_id', 'fail_fast'):
         val = getattr(build_opts, key)
         if val is not None:
@@ -4856,7 +4856,7 @@ def handle_add_tag(goptions, session, args):
     if options.parent:
         opts['parent'] = options.parent
     if options.arches:
-        opts['arches'] = parse_arches(options.arches)
+        opts['arches'] = koji.parse_arches(options.arches)
     if options.maven_support:
         opts['maven_support'] = True
     if options.include_all:
@@ -4898,7 +4898,7 @@ def handle_edit_tag(goptions, session, args):
     tag = args[0]
     opts = {}
     if options.arches:
-        opts['arches'] = parse_arches(options.arches)
+        opts['arches'] = koji.parse_arches(options.arches)
     if options.no_perm:
         opts['perm_id'] = None
     elif options.perm:
@@ -6270,7 +6270,7 @@ def handle_set_pkg_arches(goptions, session, args):
         parser.error(_("Please specify an archlist, a tag, and at least one package"))
         assert False  # pragma: no cover
     activate_session(session, goptions)
-    arches = parse_arches(args[0])
+    arches = koji.parse_arches(args[0])
     tag = args[1]
     for package in args[2:]:
         #really should implement multicall...
diff --git a/cli/koji_cli/lib.py b/cli/koji_cli/lib.py
index 8e8bf99a..5d779542 100644
--- a/cli/koji_cli/lib.py
+++ b/cli/koji_cli/lib.py
@@ -20,6 +20,8 @@ except ImportError:  # pragma: no cover
 
 import koji
 from koji.util import to_list
+# import parse_arches to current namespace for backward compatibility
+from koji import parse_arches
 
 # for compatibility with plugins based on older version of lib
 # Use optparse imports directly in new code.
@@ -132,26 +134,6 @@ def print_task_recurse(task,depth=0):
         print_task_recurse(child,depth+1)
 
 
-def parse_arches(arches, to_list=False):
-    """Normalize user input for a list of arches.
-
-    This method parses a single comma- or space-separated string of arches and
-    returns a space-separated string.
-
-    :param str arches: comma- or space-separated string of arches, eg.
-                       "x86_64,ppc64le", or "x86_64 ppc64le"
-    :param bool to_list: return a list of each arch, instead of a single
-                         string. This is False by default.
-    :returns: a space-separated string like "x86_64 ppc64le", or a list like
-              ['x86_64', 'ppc64le'].
-    """
-    arches = arches.replace(',', ' ').split()
-    if to_list:
-        return arches
-    else:
-        return ' '.join(arches)
-
-
 class TaskWatcher(object):
 
     def __init__(self,task_id,session,level=0,quiet=False):
diff --git a/hub/kojihub.py b/hub/kojihub.py
index 9eb78519..99453f42 100644
--- a/hub/kojihub.py
+++ b/hub/kojihub.py
@@ -886,7 +886,7 @@ def _pkglist_add(tag_id, pkg_id, owner, block, extra_arches):
     data = dslice(locals(), ('tag_id', 'owner', 'extra_arches'))
     data['package_id'] = pkg_id
     data['blocked'] = block
-    validate_arches_string(data['extra_arches'])
+    data['extra_arches'] = koji.parse_arches(data['extra_arches'], strict=True, allow_none=True)
     _pkglist_remove(tag_id, pkg_id)
     insert = InsertProcessor('tag_packages', data=data)
     insert.make_create()  #XXX user_id?
@@ -925,7 +925,7 @@ def _direct_pkglist_add(taginfo, pkginfo, owner, block, extra_arches, force,
     if not pkg:
         pkg = lookup_package(pkginfo, create=True)
     # validate arches before running callbacks
-    validate_arches_string(extra_arches)
+    extra_arches = koji.parse_arches(extra_arches, strict=True, allow_none=True)
     koji.plugin.run_callbacks('prePackageListChange', action=action, tag=tag, package=pkg, owner=owner,
                               block=block, extra_arches=extra_arches, force=force, update=update)
     # first check to see if package is:
@@ -3024,16 +3024,6 @@ def lookup_build_target(info, strict=False, create=False):
     return lookup_name('build_target', info, strict, create)
 
 
-def validate_arches_string(arches, strict=True):
-    """run checks against architectures space-separated strings"""
-    if re.match(r'^[a-zA-Z0-9_\- ]+$', arches):
-        return True
-    elif strict:
-        raise koji.GenericError("Architecture can be only [a-zA-Z0-9_-]")
-    else:
-        return False
-
-
 def create_tag(name, parent=None, arches=None, perm=None, locked=False, maven_support=False, maven_include_all=False, extra=None):
     """Create a new tag"""
     context.session.assertPerm('admin')
@@ -3048,8 +3038,7 @@ def _create_tag(name, parent=None, arches=None, perm=None, locked=False, maven_s
         raise koji.GenericError("Tag name %s is too long. Max length is %s characters",
                                 name, max_name_length)
 
-    if arches is not None:
-        validate_arches_string(arches)
+    arches = koji.parse_arches(arches, strict=True, allow_none=True)
 
     if not context.opts.get('EnableMaven') and (maven_support or maven_include_all):
         raise koji.GenericError("Maven support not enabled")
@@ -3234,7 +3223,7 @@ WHERE id = %(tagID)i"""
     # sanitize architecture names (space-separated string)
     arches = kwargs.get('arches')
     if arches and tag['arches'] != arches:
-        validate_arches_string(arches)
+        kwargs['arches'] = koji.parse_arches(arches, strict=True, allow_none=True)
 
     #check for changes
     data = tag.copy()
diff --git a/koji/__init__.py b/koji/__init__.py
index dfe35e9a..4388e8b2 100644
--- a/koji/__init__.py
+++ b/koji/__init__.py
@@ -1104,6 +1104,37 @@ def canonArch(arch):
     else:
         return arch
 
+def parse_arches(arches, to_list=False, strict=False, allow_none=False):
+    """Normalize user input for a list of arches.
+
+    This method parses a single comma- or space-separated string of arches and
+    returns a space-separated string.
+
+    Raise an error if arches string contain non-allowed characters. In strict
+    version allow only space-separated strings (db input).
+
+    :param str arches: comma- or space-separated string of arches, eg.
+                       "x86_64,ppc64le", or "x86_64 ppc64le"
+    :param bool to_list: return a list of each arch, instead of a single
+                         string. This is False by default.
+    :param bool allow_none: convert None to ""
+    :returns: a space-separated string like "x86_64 ppc64le", or a list like
+              ['x86_64', 'ppc64le'].
+    """
+    if allow_none and arches is None:
+        arches = ''
+    if not strict:
+        arches = arches.replace(',', ' ')
+    if not re.match(r'^[a-zA-Z0-9_\- ]*$', arches):
+        raise GenericError("Architecture can be only [a-zA-Z0-9_-]")
+
+    arches = arches.split()
+    if to_list:
+        return arches
+    else:
+        return ' '.join(arches)
+
+
 class POMHandler(xml.sax.handler.ContentHandler):
     def __init__(self, values, fields):
         xml.sax.handler.ContentHandler.__init__(self)
diff --git a/tests/test_hub/test_validate_arches_string.py b/tests/test_hub/test_validate_arches_string.py
deleted file mode 100644
index 9261421a..00000000
--- a/tests/test_hub/test_validate_arches_string.py
+++ /dev/null
@@ -1,25 +0,0 @@
-# coding: utf-8
-from __future__ import absolute_import
-try:
-    import unittest2 as unittest
-except ImportError:
-    import unittest
-import koji
-import kojihub
-
-class TestValidateArchesString(unittest.TestCase):
-    def test_valid_arches(self):
-        kojihub.validate_arches_string('i386')
-        kojihub.validate_arches_string('i386 x86_64')
-        kojihub.validate_arches_string('i386 x86_64   ')
-
-    def test_invalid_arches(self):
-        with self.assertRaises(koji.GenericError):
-            kojihub.validate_arches_string(u'ěšč')
-
-        with self.assertRaises(koji.GenericError):
-            kojihub.validate_arches_string(u'i386;x86_64')
-
-        with self.assertRaises(koji.GenericError):
-            kojihub.validate_arches_string(u'i386,x86_64')
-
diff --git a/tests/test_lib/test_parse_arches.py b/tests/test_lib/test_parse_arches.py
new file mode 100644
index 00000000..a5aaeac8
--- /dev/null
+++ b/tests/test_lib/test_parse_arches.py
@@ -0,0 +1,31 @@
+# coding: utf-8
+from __future__ import absolute_import
+try:
+    import unittest2 as unittest
+except ImportError:
+    import unittest
+import koji
+
+class TestParseArchesString(unittest.TestCase):
+    def test_parse_valid_arches(self):
+        r = koji.parse_arches('i386', to_list=True)
+        self.assertEqual(['i386'], r)
+
+        r = koji.parse_arches('i386 x86_64', to_list=True)
+        self.assertEqual(['i386', 'x86_64'], r)
+
+        r = koji.parse_arches('i386 x86_64   ', to_list=True)
+        self.assertEqual(['i386', 'x86_64'], r)
+
+        r = koji.parse_arches('i386,x86_64', to_list=True)
+        self.assertEqual(['i386', 'x86_64'], r)
+
+    def test_parse_invalid_arches(self):
+        with self.assertRaises(koji.GenericError):
+            koji.parse_arches(u'ěšč')
+
+        with self.assertRaises(koji.GenericError):
+            koji.parse_arches(u'i386;x86_64')
+
+        with self.assertRaises(koji.GenericError):
+            koji.parse_arches(u'i386,x86_64', strict=True)