diff --git a/com.unity.ml-agents/Runtime/Actuators/IActionReceiver.cs b/com.unity.ml-agents/Runtime/Actuators/IActionReceiver.cs
index d020dad2e9..4736e34c2b 100644
--- a/com.unity.ml-agents/Runtime/Actuators/IActionReceiver.cs
+++ b/com.unity.ml-agents/Runtime/Actuators/IActionReceiver.cs
@@ -156,7 +156,7 @@ public override int GetHashCode()
         /// <param name="destination">A float array to pack actions into whose length is greater than or
         /// equal to the addition of the Lengths of this objects <see cref="ContinuousActions"/> and
         /// <see cref="DiscreteActions"/> segments.</param>
-        /// [Obsolete("PackActions has been deprecated.")]
+        [Obsolete("PackActions has been deprecated.")]
         public void PackActions(in float[] destination)
         {
             Debug.Assert(destination.Length >= ContinuousActions.Length + DiscreteActions.Length,
diff --git a/com.unity.ml-agents/Runtime/Agent.cs b/com.unity.ml-agents/Runtime/Agent.cs
index 195566d3e2..f28c88a5d9 100644
--- a/com.unity.ml-agents/Runtime/Agent.cs
+++ b/com.unity.ml-agents/Runtime/Agent.cs
@@ -886,7 +886,11 @@ public virtual void Initialize() { }
         /// <seealso cref="IActionReceiver.OnActionReceived"/>
         public virtual void Heuristic(in ActionBuffers actionsOut)
         {
-            // For backward compatibility
+            // Disable deprecation warnings so we can call the legacy overload.
+#pragma warning disable CS0618
+
+            // The default implementation of Heuristic calls the
+            // obsolete version for backward compatibility
             switch (m_PolicyFactory.BrainParameters.VectorActionSpaceType)
             {
                 case SpaceType.Continuous:
@@ -904,6 +908,8 @@ public virtual void Heuristic(in ActionBuffers actionsOut)
                     actionsOut.ContinuousActions.Clear();
                     break;
             }
+#pragma warning restore CS0618
+
         }
 
         /// <summary>
@@ -1151,7 +1157,10 @@ public virtual void WriteDiscreteActionMask(IDiscreteActionMask actionMask)
             {
                 m_ActionMasker = new DiscreteActionMasker(actionMask);
             }
+            // Disable deprecation warnings so we can call the legacy overload.
+#pragma warning disable CS0618
             CollectDiscreteActionMasks(m_ActionMasker);
+#pragma warning restore CS0618
         }
 
         /// <summary>
@@ -1232,7 +1241,10 @@ public virtual void OnActionReceived(ActionBuffers actions)
             {
                 m_LegacyActionCache = Array.ConvertAll(actions.DiscreteActions.Array, x => (float)x);
             }
+            // Disable deprecation warnings so we can call the legacy overload.
+#pragma warning disable CS0618
             OnActionReceived(m_LegacyActionCache);
+#pragma warning restore CS0618
         }
 
         /// <summary>
diff --git a/com.unity.ml-agents/Runtime/Agent.deprecated.cs b/com.unity.ml-agents/Runtime/Agent.deprecated.cs
index 98015eff63..582882637f 100644
--- a/com.unity.ml-agents/Runtime/Agent.deprecated.cs
+++ b/com.unity.ml-agents/Runtime/Agent.deprecated.cs
@@ -9,6 +9,7 @@ public partial class Agent
         /// Deprecated, use <see cref="WriteDiscreteActionMask"/> instead.
         /// </summary>
         /// <param name="actionMasker"></param>
+        [Obsolete("CollectDiscreteActionMasks has been deprecated, please use WriteDiscreteActionMask.")]
         public virtual void CollectDiscreteActionMasks(DiscreteActionMasker actionMasker)
         {
         }
@@ -17,6 +18,7 @@ public virtual void CollectDiscreteActionMasks(DiscreteActionMasker actionMasker
         /// Deprecated, use <see cref="Heuristic(in ActionBuffers)"/> instead.
         /// </summary>
         /// <param name="actionsOut"></param>
+        [Obsolete("The float[] version of Heuristic has been deprecated, please use the ActionBuffers version instead.")]
         public virtual void Heuristic(float[] actionsOut)
         {
             Debug.LogWarning("Heuristic method called but not implemented. Returning placeholder actions.");
@@ -27,6 +29,7 @@ public virtual void Heuristic(float[] actionsOut)
         /// Deprecated, use <see cref="OnActionReceived(ActionBuffers)"/> instead.
         /// </summary>
         /// <param name="vectorAction"></param>
+        [Obsolete("The float[] version of OnActionReceived has been deprecated, please use the ActionBuffers version instead.")]
         public virtual void OnActionReceived(float[] vectorAction) { }
 
         /// <summary>
@@ -36,7 +39,7 @@ public virtual void OnActionReceived(float[] vectorAction) { }
         /// The last action that was decided by the Agent (or null if no decision has been made).
         /// </returns>
         /// <seealso cref="OnActionReceived(ActionBuffers)"/>
-        // [Obsolete("GetAction has been deprecated, please use GetStoredActionBuffers, Or GetStoredDiscreteActions.")]
+        [Obsolete("GetAction has been deprecated, please use GetStoredActionBuffers instead.")]
         public float[] GetAction()
         {
             var storedAction = m_Info.storedVectorActions;
diff --git a/com.unity.ml-agents/Runtime/Communicator/GrpcExtensions.cs b/com.unity.ml-agents/Runtime/Communicator/GrpcExtensions.cs
index 5768b2989c..28a79977f9 100644
--- a/com.unity.ml-agents/Runtime/Communicator/GrpcExtensions.cs
+++ b/com.unity.ml-agents/Runtime/Communicator/GrpcExtensions.cs
@@ -101,6 +101,8 @@ public static List<ObservationSummary> GetObservationSummaries(this AgentInfoAct
         /// <param name="isTraining">Whether or not the Brain is training.</param>
         public static BrainParametersProto ToProto(this BrainParameters bp, string name, bool isTraining)
         {
+            // Disable deprecation warnings so we can set legacy fields
+#pragma warning disable CS0618
             var brainParametersProto = new BrainParametersProto
             {
                 VectorActionSpaceTypeDeprecated = (SpaceTypeProto)bp.VectorActionSpaceType,
@@ -116,6 +118,7 @@ public static BrainParametersProto ToProto(this BrainParameters bp, string name,
             {
                 brainParametersProto.VectorActionDescriptionsDeprecated.AddRange(bp.VectorActionDescriptions);
             }
+#pragma warning restore CS0618
             return brainParametersProto;
         }
 
diff --git a/com.unity.ml-agents/Runtime/Policies/BrainParameters.cs b/com.unity.ml-agents/Runtime/Policies/BrainParameters.cs
index 1ae30a95e8..d0375d6d90 100644
--- a/com.unity.ml-agents/Runtime/Policies/BrainParameters.cs
+++ b/com.unity.ml-agents/Runtime/Policies/BrainParameters.cs
@@ -78,7 +78,7 @@ public ActionSpec ActionSpec
         /// the action.
         /// For the discrete action space: the number of branches in the action space.
         /// </value>
-        /// [Obsolete("VectorActionSize has been deprecated, please use ActionSpec instead.")]
+        [Obsolete("VectorActionSize has been deprecated, please use ActionSpec instead.")]
         [FormerlySerializedAs("vectorActionSize")]
         public int[] VectorActionSize = new[] { 1 };
 
@@ -91,7 +91,7 @@ public ActionSpec ActionSpec
         /// <summary>
         /// (Deprecated) Defines if the action is discrete or continuous.
         /// </summary>
-        /// [Obsolete("VectorActionSpaceType has been deprecated, please use ActionSpec instead.")]
+        [Obsolete("VectorActionSpaceType has been deprecated, please use ActionSpec instead.")]
         [FormerlySerializedAs("vectorActionSpaceType")]
         public SpaceType VectorActionSpaceType = SpaceType.Discrete;
 
@@ -102,7 +102,7 @@ public ActionSpec ActionSpec
         /// <summary>
         /// (Deprecated) The number of actions specified by this Brain.
         /// </summary>
-        /// [Obsolete("NumActions has been deprecated, please use ActionSpec instead.")]
+        [Obsolete("NumActions has been deprecated, please use ActionSpec instead.")]
         public int NumActions
         {
             get
@@ -117,6 +117,8 @@ public int NumActions
         /// <returns> A new BrainParameter object with the same values as the original.</returns>
         public BrainParameters Clone()
         {
+            // Disable deprecation warnings so we can read/write the old fields.
+#pragma warning disable CS0618
             return new BrainParameters
             {
                 VectorObservationSize = VectorObservationSize,
@@ -126,6 +128,7 @@ public BrainParameters Clone()
                 VectorActionSize = (int[])VectorActionSize.Clone(),
                 VectorActionSpaceType = VectorActionSpaceType,
             };
+#pragma warning restore CS0618
         }
 
         /// <summary>
@@ -133,6 +136,8 @@ public BrainParameters Clone()
         /// </summary>
         private void UpdateToActionSpec()
         {
+            // Disable deprecation warnings so we can read the old fields.
+#pragma warning disable CS0618
             if (!hasUpgradedBrainParametersWithActionSpec
                 && m_ActionSpec.NumContinuousActions == 0
                 && m_ActionSpec.BranchSizes == null)
@@ -149,6 +154,7 @@ private void UpdateToActionSpec()
                 }
             }
             hasUpgradedBrainParametersWithActionSpec = true;
+#pragma warning restore CS0618
         }
 
         /// <summary>
@@ -156,6 +162,9 @@ private void UpdateToActionSpec()
         /// </summary>
         private void SyncDeprecatedActionFields()
         {
+            // Disable deprecation warnings so we can read the old fields.
+#pragma warning disable CS0618
+
             if (m_ActionSpec.NumContinuousActions == 0)
             {
                 VectorActionSize = (int[])ActionSpec.BranchSizes.Clone();
@@ -170,6 +179,7 @@ private void SyncDeprecatedActionFields()
             {
                 VectorActionSize = null;
             }
+#pragma warning restore CS0618
         }
 
         /// <summary>
diff --git a/com.unity.ml-agents/Tests/Editor/MLAgentsEditModeTest.cs b/com.unity.ml-agents/Tests/Editor/MLAgentsEditModeTest.cs
index b7b70f1c81..e8be0c36bb 100644
--- a/com.unity.ml-agents/Tests/Editor/MLAgentsEditModeTest.cs
+++ b/com.unity.ml-agents/Tests/Editor/MLAgentsEditModeTest.cs
@@ -711,8 +711,16 @@ public void TestHeuristicPolicyStepsSensors()
             Assert.AreEqual(numSteps, agent1.sensor1.numWriteCalls);
             Assert.AreEqual(numSteps, agent1.sensor2.numCompressedCalls);
 
+            // Disable deprecation warnings so we can read/write the old fields.
+#pragma warning disable CS0618
+
             // Make sure the Heuristic method read the observation and set the action
             Assert.AreEqual(agent1.collectObservationsCallsForEpisode, agent1.GetAction()[0]);
+            Assert.AreEqual(
+                agent1.collectObservationsCallsForEpisode,
+                agent1.GetStoredActionBuffers().ContinuousActions[0]
+            );
+#pragma warning restore CS0618
         }
     }