diff --git a/squiggle_more.c b/squiggle_more.c
index 8badbc7..ceeafd9 100644
--- a/squiggle_more.c
+++ b/squiggle_more.c
@@ -336,9 +336,9 @@ void array_print_90_ci_histogram(double* xs, int n_samples, int n_bins){
     // Fill the bins with sample counts
     int below_min = 0, above_max = 0;
     for (int i = 0; i < n_samples; i++) {
-        if(x[i] < min_value){
+        if(xs[i] < min_value){
             below_min++;
-        }else if (x[i] > max_value){
+        }else if (xs[i] > max_value){
             above_max++;
         }else{
             int bin_index = (int)((xs[i] - min_value) / bin_width);