diff --git a/sample/simple3DFilter.cpp b/sample/simple3DFilter.cpp
index e075b06..52d48aa 100644
--- a/sample/simple3DFilter.cpp
+++ b/sample/simple3DFilter.cpp
@@ -84,6 +84,7 @@ int main(int argc, char **argv) {
   char *fname1, *outFile;
   double rLimit, boxsize, rLimit2, cx, cy, cz;
   int Nres;
+  int periodic;
 
   MiniArgDesc args[] = {{"INPUT DATA1", &fname1, MINIARG_STRING},
                         {"RADIUS LIMIT", &rLimit, MINIARG_DOUBLE},
@@ -93,6 +94,7 @@ int main(int argc, char **argv) {
                         {"CY", &cy, MINIARG_DOUBLE},
                         {"CZ", &cz, MINIARG_DOUBLE},
                         {"OUTPUT FILE", &outFile, MINIARG_STRING},
+                        {"PERIODIC", &periodic, MINIARG_INT},
                         {0, 0, MINIARG_NULL}};
 
   if (!parseMiniArgs(argc, argv, args))
@@ -148,6 +150,7 @@ int main(int argc, char **argv) {
 
   cout << "Building trees..." << endl;
   MyTree tree1(allCells_1, N1_points);
+  tree1.setPeriodic(periodic != 0);
 
   cout << "Creating smoothing filter..." << endl;