diff --git a/tetrad-lib/src/main/java/edu/cmu/tetrad/search/DeltaSextadTest.java b/tetrad-lib/src/main/java/edu/cmu/tetrad/search/DeltaSextadTest.java
index c22ade5900..f8762ad67d 100644
--- a/tetrad-lib/src/main/java/edu/cmu/tetrad/search/DeltaSextadTest.java
+++ b/tetrad-lib/src/main/java/edu/cmu/tetrad/search/DeltaSextadTest.java
@@ -364,13 +364,13 @@ private double r(double array1[], double array2[], int N) {
 
     private int dofDrton(int n) {
         int dof = ((n - 2) * (n - 3)) / 2 - 2;
-        if (dof < 0) dof = 0;
+        if (dof < 1) dof = 1;
         return dof;
     }
 
     private int dofHarman(int n) {
         int dof = n * (n - 5) / 2 + 1;
-        if (dof < 0) dof = 0;
+        if (dof < 1) dof = 1;
         return dof;
     }
 
diff --git a/tetrad-lib/src/test/java/edu/cmu/tetrad/test/TestDeltaSextadTest.java b/tetrad-lib/src/test/java/edu/cmu/tetrad/test/TestDeltaSextadTest.java
index 85402f9960..207f8d0c24 100644
--- a/tetrad-lib/src/test/java/edu/cmu/tetrad/test/TestDeltaSextadTest.java
+++ b/tetrad-lib/src/test/java/edu/cmu/tetrad/test/TestDeltaSextadTest.java
@@ -144,7 +144,7 @@ public void testBollenExampleb() {
 
         IntSextad[] _sextads = {t2, t5, t10, t3, t6};
         double p = test.getPValue(_sextads);
-        assertEquals(0.90, p, 0.01);
+        assertEquals(0.21, p, 0.01);
 
         _sextads = new IntSextad[] {t10};
         p = test.getPValue(_sextads);