diff --git a/DLASystem.cpp b/DLASystem.cpp
index 75cf08d..78b51c9 100644
--- a/DLASystem.cpp
+++ b/DLASystem.cpp
@@ -148,12 +148,12 @@ void DLASystem::updateClusterRadius(double pos[]) {
 
 // make a random move of the last particle in the particleList
 void DLASystem::moveLastParticle() {
-    int rr = rgen.randomInt(4);  // pick a random number in the range 0-3, which direction do we hop?
+    int direction = rgen.randomInt(4);  // pick a random number in the range 0-3, which direction do we hop?
     double newpos[2];
 
     Particle *lastP = particleList[this->particleList.size() - 1];
 
-    setPosNeighbour(newpos, lastP->pos, rr);
+    setPosNeighbour(newpos, lastP->pos, direction);
 
     if (distanceFromOrigin(newpos) > killCircle) {
         setGrid(lastP->pos, 0);
@@ -173,10 +173,9 @@ void DLASystem::moveLastParticle() {
             updateClusterRadius(lastP->pos);  // update the cluster radius, addCircle, etc.
         }
     } else {
-        // if we get to here then we are trying to move to an occupied site
-        // (this should never happen as long as the sticking probability is 1.0)
-        cout << "reject " << rr << endl;
-        cout << lastP->pos[0] << " " << lastP->pos[1] << endl;
+        // If we get to here then we are trying to move to an occupied site
+        cout << "reject " << direction << endl
+             << lastP->pos[0] << "," << lastP->pos[1] << endl;
     }
 }
 
diff --git a/Makefile b/Makefile
index 354e5db..1397565 100644
--- a/Makefile
+++ b/Makefile
@@ -10,7 +10,7 @@
 
 CXX     = clang++
 
-CXXFLAGS = -Wall -Wextra -g -O0 
+CXXFLAGS = -Wall -Wextra -g -O0 -std=c++20 -stdlib=libc++
 
 IFLAGS = -I/usr/local/include -I/usr/include