diff --git a/include/wtsapi32.h b/include/wtsapi32.h
index 246adcf..a6a777c 100644
--- a/include/wtsapi32.h
+++ b/include/wtsapi32.h
@@ -45,6 +45,49 @@
     WTSClientProtocolType,
 } WTS_INFO_CLASS;
 
+typedef enum _WTS_CONNECTSTATE_CLASS
+{
+    WTSActive,
+    WTSConnected,
+    WTSConnectQuery,
+    WTSShadow,
+    WTSDisconnected,
+    WTSIdle,
+    WTSListen,
+    WTSReset,
+    WTSDown,
+    WTSInit
+} WTS_CONNECTSTATE_CLASS;
+
+typedef struct _WTS_PROCESS_INFOA
+{
+    DWORD SessionId;
+    DWORD ProcessId;
+    LPSTR pProcessName;
+    PSID pUserSid;
+} WTS_PROCESS_INFOA, *PWTS_PROCESS_INFOA;
+
+typedef struct _WTS_PROCESS_INFOW
+{
+    DWORD SessionId;
+    DWORD ProcessId;
+    LPWSTR pProcessName;
+    PSID pUserSid;
+} WTS_PROCESS_INFOW, *PWTS_PROCESS_INFOW;
+
+typedef struct _WTS_SESSION_INFOA
+{
+    DWORD SessionId;
+    LPSTR pWinStationName;
+    WTS_CONNECTSTATE_CLASS State;
+} WTS_SESSION_INFOA, *PWTS_SESSION_INFOA;
+
+typedef struct _WTS_SESSION_INFOW
+{
+    DWORD SessionId;
+    LPWSTR pWinStationName;
+    WTS_CONNECTSTATE_CLASS State;
+} WTS_SESSION_INFOW, *PWTS_SESSION_INFOW;
 
 BOOL WINAPI WTSQuerySessionInformationW(
     HANDLE hServer,