diff --git a/src/icepack2/model/minimization.py b/src/icepack2/model/minimization.py
index 6746fcc..324639c 100644
--- a/src/icepack2/model/minimization.py
+++ b/src/icepack2/model/minimization.py
@@ -30,7 +30,8 @@ def viscous_power(**kwargs):
     A, n = map(kwargs.get, parameter_names)
 
     mesh = ufl.domain.extract_unique_domain(M)
-    d = mesh.geometric_dimension()
+    d = mesh.geometric_dimension          # FD2026: attribute; FD<=2025: method
+    d = d() if callable(d) else d
 
     M_2 = (inner(M, M) - tr(M) ** 2 / (d + 1)) / 2
     M_n = conditional(eq(n, 1), M_2, M_2 ** ((n + 1) / 2))
diff --git a/src/icepack2/model/variational.py b/src/icepack2/model/variational.py
index 599e23a..97d48b5 100644
--- a/src/icepack2/model/variational.py
+++ b/src/icepack2/model/variational.py
@@ -29,7 +29,8 @@ def flow_law(**kwargs):
     A, n = map(kwargs.get, ("flow_law_coefficient", "flow_law_exponent"))
 
     mesh = ufl.domain.extract_unique_domain(u)
-    d = mesh.geometric_dimension()
+    d = mesh.geometric_dimension          # FD2026: attribute; FD<=2025: method
+    d = d() if callable(d) else d
 
     ε = sym(grad(u))
     M_2 = (inner(M, M) - tr(M) ** 2 / (d + 1)) / 2