4 files changed, 9 insertions, 3 deletions

diff --git a/pyecsca/ec/coordinates.py b/pyecsca/ec/coordinates.py
index f15a64b..f356b66 100644
--- a/pyecsca/ec/coordinates.py
+++ b/pyecsca/ec/coordinates.py
@@ -6,7 +6,7 @@ from typing import List, Any, MutableMapping
 
 from public import public
 
-from .formula import Formula
+from .formula.base import Formula
 from .formula.efd import (
     EFDFormula,
     AdditionEFDFormula,
diff --git a/pyecsca/ec/divpoly.py b/pyecsca/ec/divpoly.py
index 9956335..798bffd 100644
--- a/pyecsca/ec/divpoly.py
+++ b/pyecsca/ec/divpoly.py
@@ -249,6 +249,12 @@ if has_pari:
 
     def mult_by_n_pari(curve: EllipticCurve, n: int):
         pari = cypari2.Pari()
+        # Magic heuristic, plus some constant term for very small polys
+        stacksize = 2 * (n**2 * (40 * curve.prime.bit_length())) + 1000000
+        stacksizemax = 15 * stacksize
+
+        pari.default("debugmem", 0)  # silence stack warnings
+        pari.allocatemem(stacksize, stacksizemax, silent=True)
         p = pari(curve.prime)
         a = pari.Mod(curve.parameters["a"], p)
         b = pari.Mod(curve.parameters["b"], p)
diff --git a/pyecsca/ec/formula/efd.py b/pyecsca/ec/formula/efd.py
index edf64de..b74b504 100644
--- a/pyecsca/ec/formula/efd.py
+++ b/pyecsca/ec/formula/efd.py
@@ -6,7 +6,7 @@ from public import public
 from importlib_resources.abc import Traversable
 from typing import Any
 
-from . import CodeFormula
+from .code import CodeFormula
 from .base import (
     Formula,
     CodeOp,
diff --git a/pyecsca/ec/formula/expand.py b/pyecsca/ec/formula/expand.py
index 638fcfc..acaf7ea 100644
--- a/pyecsca/ec/formula/expand.py
+++ b/pyecsca/ec/formula/expand.py
@@ -1,7 +1,7 @@
 from typing import Set, Callable, Any
 from public import public
 
-from . import Formula
+from .base import Formula
 from .efd import EFDFormula
 from .fliparoo import recursive_fliparoo
 from .metrics import ivs_norm