diff --git a/src/distance.c b/src/distance.c
index 1afdd03..85f0598 100755
--- a/src/distance.c
+++ b/src/distance.c
@@ -121,7 +121,7 @@ static double canberra(double *x, double *y, int nx, int ny, int nc)
     dist  = 0;
     for (j = 0 ;j < nc; j++) {
         if (both_non_NA(*x, *y)) {
-            sum = fabs(*x + *y);
+            sum  = fabs(*x) + fabs(*y);  // wrong denominator before
             diff = fabs(*x - *y);
             if (sum > DBL_MIN || diff > DBL_MIN) {
                 dev = diff/sum;