diff --git a/blast/src/blSection.cpp b/blast/src/blSection.cpp
index e06ae5e14c91f8a673014af9d8559a28be596446..bcae644e5a8495f764c458432e646ae918eca142 100644
--- a/blast/src/blSection.cpp
+++ b/blast/src/blSection.cpp
@@ -60,6 +60,7 @@ void Section::computeLocalCoordinates()
             auto &nod2 = bl->nodes[ielm];
             double dx = std::sqrt((nod1->pos[0] - nod2->pos[0]) * (nod1->pos[0] - nod2->pos[0]) + (nod1->pos[1] - nod2->pos[1]) * (nod1->pos[1] - nod2->pos[1]));
             nod1->xi = nod2->xi + dx;
+            nod1->xiExt = nod1->xi;
         }
         // Compute the x/c coordinate.
         for (auto &inod : bl->nodes)