diff --git a/rtamt/pastifier/ltl/pastifier.py b/rtamt/pastifier/ltl/pastifier.py
index 31220f72..22861e59 100644
--- a/rtamt/pastifier/ltl/pastifier.py
+++ b/rtamt/pastifier/ltl/pastifier.py
@@ -33,8 +33,10 @@ class LtlPastifier(LtlAstVisitor):
 
     def __init__(self):
         self.subformula_horizons = dict()
+        self.ast = None
 
     def pastify(self, ast):
+        self.ast = ast
         h = LtlHorizon()
         horizons = dict()
         for spec in ast.specs:
@@ -46,9 +48,17 @@ def pastify(self, ast):
             horizon = horizons[spec]
             pastified_spec = self.visit(spec, horizon)
             pastified_specs.append(pastified_spec)
+        ast.phi_name_to_node_dict = self.ast.phi_name_to_node_dict
         ast.specs = pastified_specs
         return ast
 
+    def visit(self, node, *args, **kwargs):
+        out = LtlAstVisitor.visit(self, node, *args, **kwargs)
+        d = self.ast.phi_name_to_node_dict
+        keys = [k for k, v in d.items() if v == node]
+        self.ast.phi_name_to_node_dict.update({key: out for key in keys})
+        return out
+
     def visitConstant(self, node, *args, **kwargs):
         node = Constant(node.val)
         return node
diff --git a/rtamt/pastifier/stl/pastifier.py b/rtamt/pastifier/stl/pastifier.py
index ee6d062a..49a3bc37 100644
--- a/rtamt/pastifier/stl/pastifier.py
+++ b/rtamt/pastifier/stl/pastifier.py
@@ -42,6 +42,7 @@ def __init__(self):
         self.node_horizons = dict()
 
     def pastify(self, ast):
+        self.ast = ast
         h = StlHorizon()
         horizons = dict()
         for spec in ast.specs:
@@ -54,10 +55,15 @@ def pastify(self, ast):
             pastified_spec = self.visit(spec, horizon)
             pastified_specs.append(pastified_spec)
         ast.specs = pastified_specs
+        ast.phi_name_to_node_dict = self.ast.phi_name_to_node_dict
         return ast
 
     def visit(self, node, *args, **kwargs):
-        return StlAstVisitor.visit(self, node, *args, **kwargs)
+        out = StlAstVisitor.visit(self, node, *args, **kwargs)
+        d = self.ast.phi_name_to_node_dict
+        keys = [k for k, v in d.items() if v == node]
+        self.ast.phi_name_to_node_dict.update({key: out for key in keys})
+        return out
 
     def visitVariable(self, node, *args, **kwargs):
         horizon = args[0]
diff --git a/setup.py b/setup.py
index 0892a157..a5eb0434 100644
--- a/setup.py
+++ b/setup.py
@@ -9,7 +9,7 @@
 
 setup(
     name='rtamt',
-    version='0.4.9',
+    version='0.4.10',
     description='Library for specification-based online monitoring.',
     long_description=long_description,
     long_description_content_type="text/markdown",