diff --git a/gtsam/inference/inference.cpp b/gtsam/inference/inference.cpp
index e1c250fcf..9b7252030 100644
--- a/gtsam/inference/inference.cpp
+++ b/gtsam/inference/inference.cpp
@@ -60,11 +60,11 @@ Permutation::shared_ptr PermutationCOLAMD_(const VariableIndex& variableIndex, s
     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[CCOLAMD_KNOBS];
-  //  ccolamd_set_defaults(knobs);
-  //  knobs[CCOLAMD_DENSE_ROW]=-1;
-  //  knobs[CCOLAMD_DENSE_COL]=-1;
+  //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 */