diff --git a/src/one-body-sample.cc b/src/one-body-sample.cc
index 9190b6b645dc36582fb92516db1d87b96edb8eb3..489f69ad58063920ead7912edbe655dcaa81e171 100644
--- a/src/one-body-sample.cc
+++ b/src/one-body-sample.cc
@@ -453,7 +453,7 @@ int main(int argc, char *argv[]) {
 
     {
       std::fstream vertexCoordinateWriter("coordinates", std::fstream::out);
-      for (size_t i = 0; i < frictionalNodes.size(); ++i)
+      for (size_t i = 0; i < fineVertexCount; ++i)
         if (frictionalNodes[i][0])
           vertexCoordinateWriter << vertexCoordinates[i] << std::endl;
       vertexCoordinateWriter.close();