diff --git a/src/main/java/gov/usgs/earthquake/nshmp/data/Sequences.java b/src/main/java/gov/usgs/earthquake/nshmp/data/Sequences.java
index 48069d86f447ecead3ee4d3f013367a5309937b5..ebba53c1ce9e125a3d9debc178eb3d9de296fc62 100644
--- a/src/main/java/gov/usgs/earthquake/nshmp/data/Sequences.java
+++ b/src/main/java/gov/usgs/earthquake/nshmp/data/Sequences.java
@@ -88,6 +88,7 @@ class Sequences {
    */
   static XySequence combine(Collection<XySequence> xySequences) {
     checkState(areSimilar(xySequences));
+    XySequence first = getFirstSequence(xySequences);
     if (xySequences.size() == 1) {
       return getFirstSequence(xySequences);
     }