diff --git a/gtsam/hybrid/HybridFactor.cpp b/gtsam/hybrid/HybridFactor.cpp
index 127c9761c..cdae5faa6 100644
--- a/gtsam/hybrid/HybridFactor.cpp
+++ b/gtsam/hybrid/HybridFactor.cpp
@@ -50,7 +50,7 @@ DiscreteKeys CollectDiscreteKeys(const DiscreteKeys &key1,
 
 /* ************************************************************************ */
 HybridFactor::HybridFactor(const KeyVector &keys)
-    : Base(keys), isContinuous_(true), nrContinuous_(keys.size()) {}
+    : Base(keys), isContinuous_(true), continuousKeys_(keys) {}
 
 /* ************************************************************************ */
 HybridFactor::HybridFactor(const KeyVector &continuousKeys,
@@ -59,8 +59,8 @@ HybridFactor::HybridFactor(const KeyVector &continuousKeys,
       isDiscrete_((continuousKeys.size() == 0) && (discreteKeys.size() != 0)),
       isContinuous_((continuousKeys.size() != 0) && (discreteKeys.size() == 0)),
       isHybrid_((continuousKeys.size() != 0) && (discreteKeys.size() != 0)),
-      nrContinuous_(continuousKeys.size()),
-      discreteKeys_(discreteKeys) {}
+      discreteKeys_(discreteKeys),
+      continuousKeys_(continuousKeys) {}
 
 /* ************************************************************************ */
 HybridFactor::HybridFactor(const DiscreteKeys &discreteKeys)
@@ -73,7 +73,8 @@ bool HybridFactor::equals(const HybridFactor &lf, double tol) const {
   const This *e = dynamic_cast<const This *>(&lf);
   return e != nullptr && Base::equals(*e, tol) &&
          isDiscrete_ == e->isDiscrete_ && isContinuous_ == e->isContinuous_ &&
-         isHybrid_ == e->isHybrid_ && nrContinuous_ == e->nrContinuous_;
+         isHybrid_ == e->isHybrid_ && continuousKeys_ == e->continuousKeys_ &&
+         discreteKeys_ == e->discreteKeys_;
 }
 
 /* ************************************************************************ */
diff --git a/gtsam/hybrid/HybridFactor.h b/gtsam/hybrid/HybridFactor.h
index 244fba4cc..ffa28d3f7 100644
--- a/gtsam/hybrid/HybridFactor.h
+++ b/gtsam/hybrid/HybridFactor.h
@@ -50,7 +50,10 @@ class GTSAM_EXPORT HybridFactor : public Factor {
   size_t nrContinuous_ = 0;
 
  protected:
+  // Set of DiscreteKeys for this factor.
   DiscreteKeys discreteKeys_;
+  // For bookkeeping
+  KeyVector continuousKeys_;
 
  public:
   // typedefs needed to play nice with gtsam
@@ -117,10 +120,13 @@ class GTSAM_EXPORT HybridFactor : public Factor {
   bool isHybrid() const { return isHybrid_; }
 
   /// Return the number of continuous variables in this factor.
-  size_t nrContinuous() const { return nrContinuous_; }
+  size_t nrContinuous() const { return continuousKeys_.size(); }
 
-  /// Return vector of discrete keys.
-  DiscreteKeys discreteKeys() const { return discreteKeys_; }
+  /// Return the discrete keys for this factor.
+  const DiscreteKeys &discreteKeys() const { return discreteKeys_; }
+
+  /// Return only the continuous keys for this factor.
+  const KeyVector &continuousKeys() const { return continuousKeys_; }
 
   /// @}
 };