diff --git a/gtsam/nonlinear/ISAM2.cpp b/gtsam/nonlinear/ISAM2.cpp
index a9bd195ba..8c470f1aa 100644
--- a/gtsam/nonlinear/ISAM2.cpp
+++ b/gtsam/nonlinear/ISAM2.cpp
@@ -86,9 +86,6 @@ ISAM2& ISAM2::operator=(const ISAM2& rhs) {
   params_ = rhs.params_;
   doglegDelta_ = rhs.doglegDelta_;
 
-#ifndef NDEBUG
-  lastRelinVariables_ = rhs.lastRelinVariables_;
-#endif
   lastAffectedVariableCount = rhs.lastAffectedVariableCount;
   lastAffectedFactorCount = rhs.lastAffectedFactorCount;
   lastAffectedCliqueCount = rhs.lastAffectedCliqueCount;
@@ -661,15 +658,8 @@ ISAM2Result ISAM2::update(
     toc(7,"expmap");
 
     result.variablesRelinearized = markedKeys.size();
-
-#ifndef NDEBUG
-    lastRelinVariables_ = markedRelinMask;
-#endif
   } else {
     result.variablesRelinearized = 0;
-#ifndef NDEBUG
-    lastRelinVariables_ = vector<bool>(ordering_.nVars(), false);
-#endif
   }
 
   tic(8,"linearize new");
diff --git a/gtsam/nonlinear/ISAM2.h b/gtsam/nonlinear/ISAM2.h
index 34fc7b46f..0d540a729 100644
--- a/gtsam/nonlinear/ISAM2.h
+++ b/gtsam/nonlinear/ISAM2.h
@@ -403,11 +403,6 @@ protected:
   /** The inverse ordering, only used for creating ISAM2Result::DetailedResults */
   boost::optional<Ordering::InvertedMap> inverseOrdering_;
 
-private:
-#ifndef NDEBUG
-  std::vector<bool> lastRelinVariables_;
-#endif
-
 public:
 
   typedef ISAM2 This; ///< This class