diff --git a/src/Microsoft.ML.Transforms/Text/LdaSingleBox.cs b/src/Microsoft.ML.Transforms/Text/LdaSingleBox.cs
index 97054d8bb8..d0d38f272b 100644
--- a/src/Microsoft.ML.Transforms/Text/LdaSingleBox.cs
+++ b/src/Microsoft.ML.Transforms/Text/LdaSingleBox.cs
@@ -8,83 +8,93 @@
 using System.Runtime.InteropServices;
 using System.Security;
 using Microsoft.ML.Runtime;
+using Microsoft.Win32.SafeHandles;
 
 namespace Microsoft.ML.TextAnalytics
 {
 
     internal static class LdaInterface
     {
-        public struct LdaEngine
+        public sealed class SafeLdaEngineHandle : SafeHandleZeroOrMinusOneIsInvalid
         {
-            public IntPtr Ptr;
+            private SafeLdaEngineHandle()
+                : base(true)
+            {
+            }
+
+            protected override bool ReleaseHandle()
+            {
+                DestroyEngine(handle);
+                return true;
+            }
         }
 
         private const string NativePath = "LdaNative";
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern LdaEngine CreateEngine(int numTopic, int numVocab, float alphaSum, float beta, int numIter,
+        internal static extern SafeLdaEngineHandle CreateEngine(int numTopic, int numVocab, float alphaSum, float beta, int numIter,
             int likelihoodInterval, int numThread, int mhstep, int maxDocToken);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void AllocateModelMemory(LdaEngine engine, int numTopic, int numVocab, long tableSize, long aliasTableSize);
+        internal static extern void AllocateModelMemory(SafeLdaEngineHandle engine, int numTopic, int numVocab, long tableSize, long aliasTableSize);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void AllocateDataMemory(LdaEngine engine, int docNum, long corpusSize);
+        internal static extern void AllocateDataMemory(SafeLdaEngineHandle engine, int docNum, long corpusSize);
 
         [DllImport(NativePath, CharSet = CharSet.Ansi), SuppressUnmanagedCodeSecurity]
-        internal static extern void Train(LdaEngine engine, string trainOutput);
+        internal static extern void Train(SafeLdaEngineHandle engine, string trainOutput);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void GetModelStat(LdaEngine engine, out long memBlockSize, out long aliasMemBlockSize);
+        internal static extern void GetModelStat(SafeLdaEngineHandle engine, out long memBlockSize, out long aliasMemBlockSize);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void Test(LdaEngine engine, int numBurninIter, float[] pLogLikelihood);
+        internal static extern void Test(SafeLdaEngineHandle engine, int numBurninIter, float[] pLogLikelihood);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void CleanData(LdaEngine engine);
+        internal static extern void CleanData(SafeLdaEngineHandle engine);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void CleanModel(LdaEngine engine);
+        internal static extern void CleanModel(SafeLdaEngineHandle engine);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void DestroyEngine(LdaEngine engine);
+        private static extern void DestroyEngine(IntPtr engine);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void GetWordTopic(LdaEngine engine, int wordId, int[] pTopic, int[] pProb, ref int length);
+        internal static extern void GetWordTopic(SafeLdaEngineHandle engine, int wordId, int[] pTopic, int[] pProb, ref int length);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void SetWordTopic(LdaEngine engine, int wordId, int[] pTopic, int[] pProb, int length);
+        internal static extern void SetWordTopic(SafeLdaEngineHandle engine, int wordId, int[] pTopic, int[] pProb, int length);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void SetAlphaSum(LdaEngine engine, float avgDocLength);
+        internal static extern void SetAlphaSum(SafeLdaEngineHandle engine, float avgDocLength);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern int FeedInData(LdaEngine engine, int[] termId, int[] termFreq, int termNum, int numVocab);
+        internal static extern int FeedInData(SafeLdaEngineHandle engine, int[] termId, int[] termFreq, int termNum, int numVocab);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern int FeedInDataDense(LdaEngine engine, int[] termFreq, int termNum, int numVocab);
+        internal static extern int FeedInDataDense(SafeLdaEngineHandle engine, int[] termFreq, int termNum, int numVocab);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void GetDocTopic(LdaEngine engine, int docId, int[] pTopic, int[] pProb, ref int numTopicReturn);
+        internal static extern void GetDocTopic(SafeLdaEngineHandle engine, int docId, int[] pTopic, int[] pProb, ref int numTopicReturn);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void GetTopicSummary(LdaEngine engine, int topicId, int[] pWords, float[] pProb, ref int numTopicReturn);
+        internal static extern void GetTopicSummary(SafeLdaEngineHandle engine, int topicId, int[] pWords, float[] pProb, ref int numTopicReturn);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void TestOneDoc(LdaEngine engine, int[] termId, int[] termFreq, int termNum, int[] pTopics, int[] pProbs, ref int numTopicsMax, int numBurnIter, bool reset);
+        internal static extern void TestOneDoc(SafeLdaEngineHandle engine, int[] termId, int[] termFreq, int termNum, int[] pTopics, int[] pProbs, ref int numTopicsMax, int numBurnIter, bool reset);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void TestOneDocDense(LdaEngine engine, int[] termFreq, int termNum, int[] pTopics, int[] pProbs, ref int numTopicsMax, int numBurninIter, bool reset);
+        internal static extern void TestOneDocDense(SafeLdaEngineHandle engine, int[] termFreq, int termNum, int[] pTopics, int[] pProbs, ref int numTopicsMax, int numBurninIter, bool reset);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void InitializeBeforeTrain(LdaEngine engine);
+        internal static extern void InitializeBeforeTrain(SafeLdaEngineHandle engine);
 
         [DllImport(NativePath), SuppressUnmanagedCodeSecurity]
-        internal static extern void InitializeBeforeTest(LdaEngine engine);
+        internal static extern void InitializeBeforeTest(SafeLdaEngineHandle engine);
     }
 
     internal sealed class LdaSingleBox : IDisposable
     {
-        private LdaInterface.LdaEngine _engine;
+        private LdaInterface.SafeLdaEngineHandle _engine;
         private bool _isDisposed;
         private int[] _topics;
         private int[] _probabilities;
@@ -358,8 +368,7 @@ public void Dispose()
             if (_isDisposed)
                 return;
             _isDisposed = true;
-            LdaInterface.DestroyEngine(_engine);
-            _engine.Ptr = IntPtr.Zero;
+            _engine.Dispose();
         }
     }
 }