diff --git a/tetrad-lib/src/main/java/edu/cmu/tetrad/search/Fas.java b/tetrad-lib/src/main/java/edu/cmu/tetrad/search/Fas.java
index 435cfbc710..cd07b3d3ac 100644
--- a/tetrad-lib/src/main/java/edu/cmu/tetrad/search/Fas.java
+++ b/tetrad-lib/src/main/java/edu/cmu/tetrad/search/Fas.java
@@ -158,7 +158,7 @@ public Graph search() {
         this.logger.log("info", "Starting Fast Adjacency Search.");
 
         sepset = new SepsetMap();
-        sepset.setReturnEmptyIfNotSet(sepsetsReturnEmptyIfNotFixed);
+//        sepset.setReturnEmptyIfNotSet(sepsetsReturnEmptyIfNotFixed);
 
         int _depth = depth;
 
diff --git a/tetrad-lib/src/main/java/edu/cmu/tetrad/search/SepsetMap.java b/tetrad-lib/src/main/java/edu/cmu/tetrad/search/SepsetMap.java
index 2c520a54fc..fde034087d 100644
--- a/tetrad-lib/src/main/java/edu/cmu/tetrad/search/SepsetMap.java
+++ b/tetrad-lib/src/main/java/edu/cmu/tetrad/search/SepsetMap.java
@@ -53,7 +53,7 @@ public final class SepsetMap implements TetradSerializable {
 
     private Map<Node, HashSet<Node>> parents = new HashMap<>();
     private Set<Set<Node>> correlations;
-    private boolean returnEmptyIfNotSet = false;
+    private boolean returnEmptyIfNotSet = true;
 
     //=============================CONSTRUCTORS===========================//
 
@@ -107,11 +107,13 @@ public List<Node> get(Node a, Node b) {
             return Collections.emptyList();
         }
 
-        if (returnEmptyIfNotSet && sepsets.get(pair) == null) {
+        List<Node> nodes = sepsets.get(pair);
+
+        if (returnEmptyIfNotSet && nodes == null) {
             return Collections.emptyList();
         }
 
-        return sepsets.get(pair);
+        return nodes;
     }
 
     public double getPValue(Node x, Node y) {
diff --git a/tetrad-lib/src/main/java/edu/cmu/tetrad/search/SepsetsSet.java b/tetrad-lib/src/main/java/edu/cmu/tetrad/search/SepsetsSet.java
index 1069845964..0c3160d630 100644
--- a/tetrad-lib/src/main/java/edu/cmu/tetrad/search/SepsetsSet.java
+++ b/tetrad-lib/src/main/java/edu/cmu/tetrad/search/SepsetsSet.java
@@ -23,6 +23,7 @@
 
 import edu.cmu.tetrad.graph.Node;
 
+import java.util.Collections;
 import java.util.List;
 
 /**
@@ -48,8 +49,7 @@ public List<Node> getSepset(Node a, Node b) {
     @Override
     public boolean isCollider(Node i, Node j, Node k) {
         List<Node> sepset = sepsets.get(i, k);
-        isIndependent(i, k, sepsets.get(i, k));
-        return sepset != null && !sepset.contains(j);
+        return !sepset.contains(j);
     }
 
     @Override