diff --git a/.gitignore b/.gitignore
index 646f537a..347f7941 100755
--- a/.gitignore
+++ b/.gitignore
@@ -2,7 +2,7 @@
 __pycache__/
 *.py[cod]
 *$py.class
-"pyreason/.cache_status.yaml
+pyreason/.cache_status.yaml
 # Cache status file when initialized
 # Keep the initial false version in repo, ignore when it becomes true
 .DS_STORE
diff --git a/tests/unit/disable_jit/interpretations/test_ground_rule_helpers.py b/tests/unit/disable_jit/interpretations/test_ground_rule_helpers.py
index c5430145..52f58c0e 100644
--- a/tests/unit/disable_jit/interpretations/test_ground_rule_helpers.py
+++ b/tests/unit/disable_jit/interpretations/test_ground_rule_helpers.py
@@ -919,6 +919,8 @@ def get_clauses(self): return self._clauses
     def get_thresholds(self): return self._thresholds
     def get_annotation_function(self): return self._ann_fn
     def get_edges(self): return self._rule_edges
+    def get_head_function(self): return ["", ""]
+    def get_head_function_vars(self): return [[], []]
 
 def _shim_typed_list(monkeypatch):
     class _ListShim:
diff --git a/tests/unit/disable_jit/interpretations/test_interpretation_common.py b/tests/unit/disable_jit/interpretations/test_interpretation_common.py
index 74a5763f..069af6b1 100644
--- a/tests/unit/disable_jit/interpretations/test_interpretation_common.py
+++ b/tests/unit/disable_jit/interpretations/test_interpretation_common.py
@@ -71,9 +71,11 @@ def add_edge(*args):
     _ground_rule_fn = _py(interpretation._ground_rule)
     if "num_ga" in inspect.signature(_ground_rule_fn).parameters:
         def ground_rule(*args, **kwargs):
+            kwargs.setdefault('head_functions', ())
             return _ground_rule_fn(*args, num_ga=[0], **kwargs)
     else:
         def ground_rule(*args, **kwargs):
+            kwargs.setdefault('head_functions', ())
             return _ground_rule_fn(*args, **kwargs)
     ns.ground_rule = ground_rule
     ns.update_rule_trace = _py(interpretation._update_rule_trace)
diff --git a/tests/unit/disable_jit/interpretations/test_interpretation_init.py b/tests/unit/disable_jit/interpretations/test_interpretation_init.py
index dcfd36ce..6d9dc0e9 100644
--- a/tests/unit/disable_jit/interpretations/test_interpretation_init.py
+++ b/tests/unit/disable_jit/interpretations/test_interpretation_init.py
@@ -76,8 +76,9 @@ def test_interpretation_init_neighbors(shim_types):
         False,
         False,
         False,
-        0,
         False,
+        "",
+        True,
     )
     assert set(interp.neighbors["n1"]) == {"n2"}
     assert set(interp.neighbors["n2"]) == {"n1"}
@@ -211,8 +212,9 @@ def build_interp():
         False,
         False,
         False,
-        0,
         False,
+        "",
+        True,
     )
     interp.time = 5
     interp.prev_reasoning_data = [2, 0]
diff --git a/tests/unit/disable_jit/interpretations/test_reason_core.py b/tests/unit/disable_jit/interpretations/test_reason_core.py
index 872c6171..1c657e2c 100644
--- a/tests/unit/disable_jit/interpretations/test_reason_core.py
+++ b/tests/unit/disable_jit/interpretations/test_reason_core.py
@@ -174,6 +174,7 @@ def is_static(self):
         "allow_ground_rules": True,
         "max_facts_time": 0,
         "annotation_functions": {},
+        "head_functions": (),
         "convergence_mode": "perfect_convergence",
         "convergence_delta": 0,
         "verbose": False,
@@ -220,6 +221,7 @@ def run(**overrides):
             params["allow_ground_rules"],
             params["max_facts_time"],
             params["annotation_functions"],
+            params["head_functions"],
             params["convergence_mode"],
             params["convergence_delta"],
             params["verbose"],