diff --git a/src/nw_analytic_hessian.py b/src/nw_analytic_hessian.py
index 828c352..ee6bf86 100644
--- a/src/nw_analytic_hessian.py
+++ b/src/nw_analytic_hessian.py
@@ -42,15 +42,16 @@ def loocv_mse(x: np.ndarray, y: np.ndarray, h: float, kernel: str) -> Tuple[floa
 
     num = w @ y
     den = w.sum(axis=1)
-    m = num / den
+    den_safe = np.where(den == 0, np.finfo(float).eps, den)  # Guard against division by zero
+    m = num / den_safe
 
     num1 = w1 @ y
     den1 = w1.sum(axis=1)
-    m1 = (num1 * den - num * den1) / (den ** 2)
+    m1 = (num1 * den_safe - num * den1) / (den_safe ** 2)
 
     num2 = w2 @ y
     den2 = w2.sum(axis=1)
-    m2 = (num2 * den - num * den2) / (den ** 2) - 2 * m1 * den1 / den
+    m2 = (num2 * den_safe - num * den2) / (den_safe ** 2) - 2 * m1 * den1 / den_safe
 
     resid = y - m
     loss = np.mean(resid**2)