diff --git a/lib/cdhc/shapiroe.c b/lib/cdhc/shapiroe.c
index 1a75b393597..05521183829 100644
--- a/lib/cdhc/shapiroe.c
+++ b/lib/cdhc/shapiroe.c
@@ -6,6 +6,7 @@ double *Cdhc_shapiro_wilk_exp(double *x, int n)
     static double y[2];
     double mean, b, s1, xs, sum1 = 0.0, sum2 = 0.0;
     int i;
+    xs = x[0];
 
     for (i = 0; i < n; ++i)
         if (i == 0 || xs > x[i])