diff --git a/src/sixtypical/model.py b/src/sixtypical/model.py
index 6b72321..230ea0b 100644
--- a/src/sixtypical/model.py
+++ b/src/sixtypical/model.py
@@ -107,6 +107,13 @@ class LocationRef(Ref):
     def is_constant(self):
         return isinstance(self.type, RoutineType)
 
+    def backpatch_labels(self, resolver):
+        if isinstance(self.type, ExecutableType):
+            t = self.type
+            t.inputs = set([resolver(w) for w in t.inputs])
+            t.outputs = set([resolver(w) for w in t.outputs])
+            t.trashes = set([resolver(w) for w in t.trashes])
+
     @classmethod
     def format_set(cls, location_refs):
         return '{%s}' % ', '.join([str(loc) for loc in sorted(location_refs)])
diff --git a/src/sixtypical/parser.py b/src/sixtypical/parser.py
index 618ea2a..eca633b 100644
--- a/src/sixtypical/parser.py
+++ b/src/sixtypical/parser.py
@@ -51,17 +51,9 @@ class Parser(object):
         self.scanner.check_type('EOF')
         # now backpatch the executable types.
         for defn in defns:
-            if isinstance(defn.location.type, VectorType):
-                t = defn.location.type
-                t.inputs = set([self.lookup(w) for w in t.inputs])
-                t.outputs = set([self.lookup(w) for w in t.outputs])
-                t.trashes = set([self.lookup(w) for w in t.trashes])
+            defn.location.backpatch_labels(lambda w: self.lookup(w))
         for routine in routines:
-            if isinstance(routine.location.type, ExecutableType):
-                t = routine.location.type
-                t.inputs = set([self.lookup(w) for w in t.inputs])
-                t.outputs = set([self.lookup(w) for w in t.outputs])
-                t.trashes = set([self.lookup(w) for w in t.trashes])
+            routine.location.backpatch_labels(lambda w: self.lookup(w))
         return Program(defns=defns, routines=routines)
 
     def defn(self):