diff --git a/molecule/specs/plugins/builtin.py b/molecule/specs/plugins/builtin.py
index 0dfd714..090951c 100644
--- a/molecule/specs/plugins/builtin.py
+++ b/molecule/specs/plugins/builtin.py
@@ -578,7 +578,6 @@ class LivecdSpec(GenericSpec):
             'extra_mkisofs_parameters': {
                 'cb': self.always_valid,
                 've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
             },
             'pre_iso_script': {
                 'cb': self.valid_exec,
diff --git a/molecule/specs/plugins/remaster.py b/molecule/specs/plugins/remaster.py
index 9b0ba3a..4ad0a42 100644
--- a/molecule/specs/plugins/remaster.py
+++ b/molecule/specs/plugins/remaster.py
@@ -322,7 +322,6 @@ class RemasterSpec(GenericSpec):
             'extra_mkisofs_parameters': {
                 'cb': self.always_valid,
                 've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
             },
             'pre_iso_script': {
                 'cb': self.valid_exec,
@@ -339,22 +338,18 @@ class RemasterSpec(GenericSpec):
             'iso_mounter': {
                 'cb': self.ne_list,
                 've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
             },
             'iso_umounter': {
                 'cb': self.ne_list,
                 've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
             },
             'squash_mounter': {
                 'cb': self.ne_list,
                 've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
             },
             'squash_umounter': {
                 'cb': self.ne_list,
                 've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
             },
             'merge_livecd_root': {
                 'cb': self.valid_dir,
@@ -370,18 +365,15 @@ class RemasterSpec(GenericSpec):
             },
             'packages_to_remove': {
                 'cb': self.ne_list,
-                've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
+                've': self.valid_comma_sep_list,
             },
             'packages_to_add': {
                 'cb': self.ne_list,
-                've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
+                've': self.valid_comma_sep_list,
             },
             'repositories_update_cmd': {
                 'cb': self.ne_list,
                 've': self.ve_string_splitter,
-                'mod': self.ve_string_splitter,
             },
             'execute_repositories_update': {
                 'cb': self.valid_ascii,
diff --git a/molecule/specs/skel.py b/molecule/specs/skel.py
index 81e0a2c..8c6166b 100644
--- a/molecule/specs/skel.py
+++ b/molecule/specs/skel.py
@@ -69,6 +69,10 @@ class GenericSpecFunctions:
             return False
         return True
 
+    def valid_comma_sep_list(self, x):
+        return [y.strip() for y in \
+            unicode(x,'raw_unicode_escape').split(",") if y.strip()]
+
     def valid_path_list(self, x):
         return [y.strip() for y in \
             unicode(x,'raw_unicode_escape').split(",") if \