diff --git a/ketrface/ketrface/dbscan.py b/ketrface/ketrface/dbscan.py
index 2aa487d..ab0ba95 100644
--- a/ketrface/ketrface/dbscan.py
+++ b/ketrface/ketrface/dbscan.py
@@ -54,6 +54,7 @@ def DBSCAN(points, eps = MAX_DISTANCE, minPts = MIN_PTS, verbose = True):
 
     sub_perc = -1
     sub_total = len(S)
+    T = S
     for j, Q in enumerate(S):                       # Process every seed point
       if verbose == True:
         sub_new_perc = int(100 * (j+1) / total)
@@ -71,7 +72,7 @@ def DBSCAN(points, eps = MAX_DISTANCE, minPts = MIN_PTS, verbose = True):
       C['faces'].append(Q)
       N = RangeQuery(points, Q, eps)  # Find neighbors
       if len(N) >= minPts:            # Density check (if Q is a core point)
-        S = Union(S, N)               # Add new neighbors to seed set
+        T = Union(T, N)               # Add new neighbors to seed set
  
   return clusters