diff --git a/gtsam/discrete/DiscreteConditional.cpp b/gtsam/discrete/DiscreteConditional.cpp
index 8c0f91807..db0ef1048 100644
--- a/gtsam/discrete/DiscreteConditional.cpp
+++ b/gtsam/discrete/DiscreteConditional.cpp
@@ -238,6 +238,7 @@ DecisionTreeFactor::shared_ptr DiscreteConditional::likelihood(
 }
 
 /* ************************************************************************** */
+#ifdef GTSAM_ALLOW_DEPRECATED_SINCE_V42
 void DiscreteConditional::solveInPlace(DiscreteValues* values) const {
   ADT pFS = Choose(*this, *values);  // P(F|S=parentsValues)
 
@@ -264,14 +265,6 @@ void DiscreteConditional::solveInPlace(DiscreteValues* values) const {
   }
 }
 
-/* ******************************************************************************** */
-void DiscreteConditional::sampleInPlace(DiscreteValues* values) const {
-  assert(nrFrontals() == 1);
-  Key j = (firstFrontalKey());
-  size_t sampled = sample(*values); // Sample variable given parents
-  (*values)[j] = sampled; // store result in partial solution
-}
-
 /* ************************************************************************** */
 size_t DiscreteConditional::solve(const DiscreteValues& parentsValues) const {
   ADT pFS = Choose(*this, parentsValues);  // P(F|S=parentsValues)
@@ -294,8 +287,17 @@ size_t DiscreteConditional::solve(const DiscreteValues& parentsValues) const {
   }
   return mpe;
 }
+#endif
 
-/* ******************************************************************************** */
+/* ************************************************************************** */
+void DiscreteConditional::sampleInPlace(DiscreteValues* values) const {
+  assert(nrFrontals() == 1);
+  Key j = (firstFrontalKey());
+  size_t sampled = sample(*values);  // Sample variable given parents
+  (*values)[j] = sampled;            // store result in partial solution
+}
+
+/* ************************************************************************** */
 size_t DiscreteConditional::sample(const DiscreteValues& parentsValues) const {
   static mt19937 rng(2);  // random number generator
 
diff --git a/gtsam/discrete/DiscreteConditional.h b/gtsam/discrete/DiscreteConditional.h
index de9d94971..ef0a4c907 100644
--- a/gtsam/discrete/DiscreteConditional.h
+++ b/gtsam/discrete/DiscreteConditional.h
@@ -179,13 +179,6 @@ class GTSAM_EXPORT DiscreteConditional
   /** Single variable version of likelihood. */
   DecisionTreeFactor::shared_ptr likelihood(size_t parent_value) const;
 
-  /**
-   * solve a conditional
-   * @param parentsValues Known values of the parents
-   * @return maximum value for the (single) frontal variable.
-   */
-  size_t solve(const DiscreteValues& parentsValues) const;
-
   /**
    * sample
    * @param parentsValues Known values of the parents
@@ -203,9 +196,6 @@ class GTSAM_EXPORT DiscreteConditional
   /// @name Advanced Interface
   /// @{
 
-  /// solve a conditional, in place
-  void solveInPlace(DiscreteValues* parentsValues) const;
-
   /// sample in place, stores result in partial solution
   void sampleInPlace(DiscreteValues* parentsValues) const;
 
@@ -228,6 +218,14 @@ class GTSAM_EXPORT DiscreteConditional
                    const Names& names = {}) const override;
 
   /// @}
+
+#ifdef GTSAM_ALLOW_DEPRECATED_SINCE_V42
+  /// @name Deprecated functionality
+  /// @{
+  size_t GTSAM_DEPRECATED solve(const DiscreteValues& parentsValues) const;
+  void GTSAM_DEPRECATED solveInPlace(DiscreteValues* parentsValues) const;
+  /// @}
+#endif
 };
 // DiscreteConditional