diff --git a/src/scgenerator/evaluator.py b/src/scgenerator/evaluator.py
index 26413b6..cd4cf84 100644
--- a/src/scgenerator/evaluator.py
+++ b/src/scgenerator/evaluator.py
@@ -510,10 +510,7 @@ default_rules: list[Rule] = [
     Rule("beta_arr", fiber.beta),
     Rule("beta1_arr", fiber.beta1),
     Rule("beta2_arr", fiber.beta2),
-    Rule(
-        "zero_dispersion_wavelength",
-        lambda beta2_arr, l: l[math.argclosest(beta2_arr, 0)],
-    ),
+    Rule("zero_dispersion_wavelength", fiber.find_zdw),
     # Fiber nonlinearity
     Rule("effective_area", fiber.effective_area_pcf),
     Rule("effective_area", fiber.effective_area_from_V, priorities=-1),
diff --git a/src/scgenerator/parameter.py b/src/scgenerator/parameter.py
index 93c716d..da296e5 100644
--- a/src/scgenerator/parameter.py
+++ b/src/scgenerator/parameter.py
@@ -336,7 +336,7 @@ class Parameters:
         literal("pcf", "marcatili", "marcatili_adjusted", "hasan", "custom"),
     )
     zero_dispersion_wavelength: float = Parameter(
-        in_range_incl(100e-9, 5000e-9), display_info=(1e9, "nm")
+        validator_list(non_negative(float, int)), display_info=(1e9, "nm")
     )
     length: float = Parameter(non_negative(float, int), display_info=(1e2, "cm"))
     capillary_num: int = Parameter(positive(int))