diff --git a/src/main/java/org/broadinstitute/hellbender/utils/MathUtils.java b/src/main/java/org/broadinstitute/hellbender/utils/MathUtils.java
index 2a258033452..a105128222f 100644
--- a/src/main/java/org/broadinstitute/hellbender/utils/MathUtils.java
+++ b/src/main/java/org/broadinstitute/hellbender/utils/MathUtils.java
@@ -524,7 +524,7 @@ public static long sum(final int[] x) {
 
     public static long sum(final long[] x) {
         Utils.nonNull(x);
-        int total = 0;
+        long total = 0;
         for (long v : x)
             total += v;
         return total;