diff --git a/python/dune/perftool/preambles.py b/python/dune/perftool/preambles.py
index 1c9008b001eeb127b9ddce1c15d4ffebef812c05..7a4dfea0389f9938b35e35726e48f939361dcbe3 100644
--- a/python/dune/perftool/preambles.py
+++ b/python/dune/perftool/preambles.py
@@ -50,6 +50,10 @@ def generate_cache_tuple(*args):
         if isinstance(data, str):
             return data
 
+        import ufl.classes
+        if isinstance(data, ufl.classes.Expr):
+            return data
+
         # Check if the given data is already hashable
         if isinstance(data, Hashable):
             if isinstance(data, Iterable):