diff --git a/inference/inference-inl.h b/inference/inference-inl.h
index 4698624b5..08322b8c3 100644
--- a/inference/inference-inl.h
+++ b/inference/inference-inl.h
@@ -371,7 +371,11 @@ Permutation::shared_ptr Inference::PermutationCOLAMD(const VARIABLEINDEXTYPE& va
     for(size_t i=0; i<nVars+1; ++i)
       cout << "p[" << i << "] = " << p[i] << endl;
 
-  double* knobs = NULL; /* colamd arg 6: parameters (uses defaults if NULL) */
+  //double* knobs = NULL; /* colamd arg 6: parameters (uses defaults if NULL) */
+  double knobs[CCOLAMD_KNOBS];
+  ccolamd_set_defaults(knobs);
+  knobs[CCOLAMD_DENSE_ROW]=-1;
+  knobs[CCOLAMD_DENSE_COL]=-1;
   int stats[CCOLAMD_STATS]; /* colamd arg 7: colamd output statistics and error codes */
 
   // call colamd, result will be in p