diff --git a/lslopt/lsldeadcode.py b/lslopt/lsldeadcode.py
index f683a08..01e481b 100644
--- a/lslopt/lsldeadcode.py
+++ b/lslopt/lsldeadcode.py
@@ -226,6 +226,14 @@ class deadcode(object):
                                 sym = self.symtab[0][subnode['name']]
                                 sym['W'] = False
                                 self.tree[sym['Loc']]['X'] = True
+                            elif subnode['nt'] in ('VECTOR', 'ROTATION'):
+                                for sub2node in subnode['ch']:
+                                    # can only happen in globals
+                                    if sub2node['nt'] == 'IDENT':
+                                        assert sub2node['scope'] == 0
+                                        sym = self.symtab[0][sub2node['name']]
+                                        sym['W'] = False
+                                        self.tree[sym['Loc']]['X'] = True
                 else:
                     self.MarkReferences(child[0])
             return True