diff --git a/artiq/compiler/types.py b/artiq/compiler/types.py
index 5e69c399f..4b6dd9a55 100644
--- a/artiq/compiler/types.py
+++ b/artiq/compiler/types.py
@@ -26,6 +26,13 @@ class UnificationError(Exception):
     def __init__(self, typea, typeb):
         self.typea, self.typeb = typea, typeb
 
+def _map_find(elts):
+    if isinstance(elts, list):
+        return [x.find() for x in elts]
+    elif isinstance(elts, dict):
+        return {k: elts[k].find() for k in elts}
+    else:
+        assert False
 
 class Type(object):
     pass
@@ -113,7 +120,7 @@ class TMono(Type):
     def __eq__(self, other):
         return isinstance(other, TMono) and \
                 self.name == other.name and \
-                self.params == other.params
+                _map_find(self.params) == _map_find(other.params)
 
     def __ne__(self, other):
         return not (self == other)
@@ -152,7 +159,7 @@ class TTuple(Type):
 
     def __eq__(self, other):
         return isinstance(other, TTuple) and \
-                self.elts == other.elts
+                _map_find(self.elts) == _map_find(other.elts)
 
     def __ne__(self, other):
         return not (self == other)
@@ -207,8 +214,8 @@ class TFunction(Type):
 
     def __eq__(self, other):
         return isinstance(other, TFunction) and \
-                self.args == other.args and \
-                self.optargs == other.optargs
+                _map_find(self.args) == _map_find(other.args) and \
+                _map_find(self.optargs) == _map_find(other.optargs)
 
     def __ne__(self, other):
         return not (self == other)