diff --git a/bin/ch/ChakraRtInterface.h b/bin/ch/ChakraRtInterface.h
index 2e7916d3297..071ff398d1b 100644
--- a/bin/ch/ChakraRtInterface.h
+++ b/bin/ch/ChakraRtInterface.h
@@ -92,7 +92,7 @@ struct JsAPIHooks
     typedef JsErrorCode(WINAPI *JsrtTTDNotifyYieldPtr)();
     typedef JsErrorCode(WINAPI *JsrtTTDHostExitPtr)(int statusCode);
 
-    typedef JsErrorCode(WINAPI *JsrtTTDGetSnapTimeTopLevelEventMovePtr)(JsRuntimeHandle runtimeHandle, JsTTDMoveMode moveMode, int64_t* targetEventTime, int64_t* targetStartSnapTime, int64_t* targetEndSnapTime);
+  typedef JsErrorCode(WINAPI *JsrtTTDGetSnapTimeTopLevelEventMovePtr)(JsRuntimeHandle runtimeHandle, JsTTDMoveMode moveMode, uint32_t kthEvent, int64_t* targetEventTime, int64_t* targetStartSnapTime, int64_t* targetEndSnapTime);
     typedef JsErrorCode(WINAPI *JsrtTTDMoveToTopLevelEventPtr)(JsRuntimeHandle runtimeHandle, JsTTDMoveMode moveMode, int64_t snapshotStartTime, int64_t eventTime);
     typedef JsErrorCode(WINAPI *JsrtTTDReplayExecutionPtr)(JsTTDMoveMode* moveMode, int64_t* rootEventTime);
 
@@ -360,7 +360,7 @@ class ChakraRTInterface
     static JsErrorCode WINAPI JsTTDNotifyYield() { return HOOK_JS_API(TTDNotifyYield()); }
     static JsErrorCode WINAPI JsTTDHostExit(int statusCode) { return HOOK_JS_API(TTDHostExit(statusCode)); }
 
-    static JsErrorCode WINAPI JsTTDGetSnapTimeTopLevelEventMove(JsRuntimeHandle runtimeHandle, JsTTDMoveMode moveMode, int64_t* targetEventTime, int64_t* targetStartSnapTime, int64_t* targetEndSnapTime) { return HOOK_JS_API(TTDGetSnapTimeTopLevelEventMove(runtimeHandle, moveMode, targetEventTime, targetStartSnapTime, targetEndSnapTime)); }
+    static JsErrorCode WINAPI JsTTDGetSnapTimeTopLevelEventMove(JsRuntimeHandle runtimeHandle, JsTTDMoveMode moveMode, uint32_t kthEvent, int64_t* targetEventTime, int64_t* targetStartSnapTime, int64_t* targetEndSnapTime) { return HOOK_JS_API(TTDGetSnapTimeTopLevelEventMove(runtimeHandle, moveMode, kthEvent, targetEventTime, targetStartSnapTime, targetEndSnapTime)); }
     static JsErrorCode WINAPI JsTTDMoveToTopLevelEvent(JsRuntimeHandle runtimeHandle, JsTTDMoveMode moveMode, int64_t snapshotStartTime, int64_t eventTime) { return HOOK_JS_API(TTDMoveToTopLevelEvent(runtimeHandle, moveMode, snapshotStartTime, eventTime)); }
     static JsErrorCode WINAPI JsTTDReplayExecution(JsTTDMoveMode* moveMode, int64_t* rootEventTime) { return HOOK_JS_API(TTDReplayExecution(moveMode, rootEventTime)); }
 
diff --git a/bin/ch/ch.cpp b/bin/ch/ch.cpp
index 113b13442b4..03e1f2f0812 100644
--- a/bin/ch/ch.cpp
+++ b/bin/ch/ch.cpp
@@ -272,13 +272,13 @@ HRESULT RunScript(const char* fileName, LPCSTR fileContents, BYTE *bcBuffer, cha
 
         try
         {
-            JsTTDMoveMode moveMode = (JsTTDMoveMode)(JsTTDMoveMode::JsTTDMoveKthEvent | ((int64) startEventCount) << 32);
+            JsTTDMoveMode moveMode = JsTTDMoveMode::JsTTDMoveKthEvent;
             int64_t snapEventTime = -1;
             int64_t nextEventTime = -2;
 
             while(true)
             {
-                JsErrorCode error = ChakraRTInterface::JsTTDGetSnapTimeTopLevelEventMove(chRuntime, moveMode, &nextEventTime, &snapEventTime, nullptr);
+                JsErrorCode error = ChakraRTInterface::JsTTDGetSnapTimeTopLevelEventMove(chRuntime, moveMode, startEventCount, &nextEventTime, &snapEventTime, nullptr);
 
                 if(error != JsNoError)
                 {
diff --git a/lib/Jsrt/ChakraCommon.h b/lib/Jsrt/ChakraCommon.h
index d36fc9cff98..d764d18135a 100644
--- a/lib/Jsrt/ChakraCommon.h
+++ b/lib/Jsrt/ChakraCommon.h
@@ -71,6 +71,7 @@ typedef BYTE* ChakraBytePtr;
 #define CHAKRA_API extern "C" SET_API_VISIBILITY JsErrorCode
 #else
 #define CHAKRA_API extern     SET_API_VISIBILITY JsErrorCode
+#include <stdbool.h>
 #endif
 
 #include <stddef.h>  // for size_t
@@ -321,7 +322,7 @@ typedef UINT32 DWORD;
     /// <summary>
     ///     An invalid runtime handle.
     /// </summary>
-    const JsRuntimeHandle JS_INVALID_RUNTIME_HANDLE = nullptr;
+    const JsRuntimeHandle JS_INVALID_RUNTIME_HANDLE = 0;
 
     /// <summary>
     ///     A reference to an object owned by the Chakra garbage collector.
@@ -338,7 +339,7 @@ typedef UINT32 DWORD;
     /// <summary>
     ///     An invalid reference.
     /// </summary>
-    const JsRef JS_INVALID_REFERENCE = nullptr;
+    const JsRef JS_INVALID_REFERENCE = 0;
 
     /// <summary>
     ///     A reference to a script context.
diff --git a/lib/Jsrt/ChakraDebug.h b/lib/Jsrt/ChakraDebug.h
index 178abf51fa5..c79262c0549 100644
--- a/lib/Jsrt/ChakraDebug.h
+++ b/lib/Jsrt/ChakraDebug.h
@@ -643,7 +643,7 @@ typedef __int64 int64_t;
     /// <summary>
     ///     TimeTravel move options as bit flag enum.
     /// </summary>
-    typedef enum _JsTTDMoveModes : int64_t
+    typedef enum _JsTTDMoveModes
     {
         /// <summary>
         ///     Indicates no special actions needed for move.
@@ -966,6 +966,7 @@ typedef __int64 int64_t;
     /// </summary>
     /// <param name="runtimeHandle">The runtime handle that the script is executing in.</param>
     /// <param name="moveMode">Flags controlling the way the move it performed and how other parameters are interpreted.</param>
+    /// <param name="kthEvent">When <c>moveMode == JsTTDMoveKthEvent</c> indicates which event, otherwise this parameter is ignored.</param>
     /// <param name="targetEventTime">The event time we want to move to or -1 if not relevant.</param>
     /// <param name="targetStartSnapTime">Out parameter with the event time of the snapshot that we should inflate from.</param>
     /// <param name="targetEndSnapTime">Optional Out parameter with the snapshot time following the event.</param>
@@ -973,6 +974,7 @@ typedef __int64 int64_t;
     CHAKRA_API JsTTDGetSnapTimeTopLevelEventMove(
         _In_ JsRuntimeHandle runtimeHandle,
         _In_ JsTTDMoveMode moveMode,
+        _In_opt_ uint32_t kthEvent,
         _Inout_ int64_t* targetEventTime,
         _Out_ int64_t* targetStartSnapTime,
         _Out_opt_ int64_t* targetEndSnapTime);
diff --git a/lib/Jsrt/Jsrt.cpp b/lib/Jsrt/Jsrt.cpp
index 2b764f8aaf8..3a857bd65f7 100644
--- a/lib/Jsrt/Jsrt.cpp
+++ b/lib/Jsrt/Jsrt.cpp
@@ -3742,8 +3742,9 @@ CHAKRA_API JsTTDCheckAndAssertIfTTDRunning(_In_ const char* msg)
 }
 
 CHAKRA_API JsTTDGetSnapTimeTopLevelEventMove(_In_ JsRuntimeHandle runtimeHandle,
-    _In_ JsTTDMoveMode moveMode, _Inout_ int64_t* targetEventTime,
-   _Out_ int64_t* targetStartSnapTime, _Out_opt_ int64_t* targetEndSnapTime)
+   _In_ JsTTDMoveMode moveMode, _In_opt_ uint32_t kthEvent,
+   _Inout_ int64_t* targetEventTime, _Out_ int64_t* targetStartSnapTime,
+   _Out_opt_ int64_t* targetEndSnapTime)
 {
 #if !ENABLE_TTD
     return JsErrorCategoryUsage;
@@ -3778,7 +3779,6 @@ CHAKRA_API JsTTDGetSnapTimeTopLevelEventMove(_In_ JsRuntimeHandle runtimeHandle,
     }
     else if((moveMode & JsTTDMoveMode::JsTTDMoveKthEvent) == JsTTDMoveMode::JsTTDMoveKthEvent)
     {
-        uint32 kthEvent = (uint32)(((int64)moveMode) >> 32);
         *targetEventTime = threadContext->TTDLog->GetKthEventTimeInLog(kthEvent);
         if(*targetEventTime == -1)
         {