diff --git a/dlls/ntdll/thread.c b/dlls/ntdll/thread.c
index 9c492659e75..bc99d1a759c 100644
--- a/dlls/ntdll/thread.c
+++ b/dlls/ntdll/thread.c
@@ -535,6 +535,7 @@ NTSTATUS WINAPI NtQueryInformationThread( HANDLE handle, THREADINFOCLASS class,
 NTSTATUS WINAPI NtSetInformationThread( HANDLE handle, THREADINFOCLASS class,
                                         LPCVOID data, ULONG length )
 {
+    NTSTATUS status;
     switch(class)
     {
     case ThreadZeroTlsCell:
@@ -577,8 +578,16 @@ NTSTATUS WINAPI NtSetInformationThread( HANDLE handle, THREADINFOCLASS class,
         {
             const HANDLE *phToken = data;
             if (length != sizeof(HANDLE)) return STATUS_INVALID_PARAMETER;
-            FIXME("Set ThreadImpersonationToken handle to %p\n", *phToken );
-            return STATUS_SUCCESS;
+            TRACE("Setting ThreadImpersonationToken handle to %p\n", *phToken );
+            SERVER_START_REQ( set_thread_info )
+            {
+                req->handle   = handle;
+                req->token    = *phToken;
+                req->mask     = SET_THREAD_INFO_TOKEN;
+                status = wine_server_call( req );
+            }
+            SERVER_END_REQ;
+            return status;
         }
     case ThreadBasicInformation:
     case ThreadTimes:
diff --git a/include/wine/server_protocol.h b/include/wine/server_protocol.h
index e86c74fc739..099e988906f 100644
--- a/include/wine/server_protocol.h
+++ b/include/wine/server_protocol.h
@@ -414,6 +414,7 @@ struct set_thread_info_request
     int          mask;
     int          priority;
     int          affinity;
+    obj_handle_t token;
 };
 struct set_thread_info_reply
 {
@@ -421,6 +422,7 @@ struct set_thread_info_reply
 };
 #define SET_THREAD_INFO_PRIORITY 0x01
 #define SET_THREAD_INFO_AFFINITY 0x02
+#define SET_THREAD_INFO_TOKEN    0x04
 
 
 
@@ -4186,6 +4188,6 @@ union generic_reply
     struct set_mailslot_info_reply set_mailslot_info_reply;
 };
 
-#define SERVER_PROTOCOL_VERSION 178
+#define SERVER_PROTOCOL_VERSION 179
 
 #endif /* __WINE_WINE_SERVER_PROTOCOL_H */
diff --git a/server/protocol.def b/server/protocol.def
index 7392ce96239..2f6556ea680 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -360,9 +360,11 @@ struct security_descriptor
     int          mask;         /* setting mask (see below) */
     int          priority;     /* priority class */
     int          affinity;     /* affinity mask */
+    obj_handle_t token;        /* impersonation token */
 @END
 #define SET_THREAD_INFO_PRIORITY 0x01
 #define SET_THREAD_INFO_AFFINITY 0x02
+#define SET_THREAD_INFO_TOKEN    0x04
 
 
 /* Retrieve information about a module */
diff --git a/server/security.h b/server/security.h
index 0be5f20dd0c..14817660363 100644
--- a/server/security.h
+++ b/server/security.h
@@ -43,6 +43,7 @@ extern struct token *token_create_admin(void);
 extern int token_check_privileges( struct token *token, int all_required,
                                    const LUID_AND_ATTRIBUTES *reqprivs,
                                    unsigned int count, LUID_AND_ATTRIBUTES *usedprivs);
+extern void security_set_thread_token( struct thread *thread, obj_handle_t handle );
 
 static inline int thread_single_check_privilege( struct thread *thread, const LUID *priv)
 {
diff --git a/server/thread.c b/server/thread.c
index 5f4fdeef1c4..c11c18ab54e 100644
--- a/server/thread.c
+++ b/server/thread.c
@@ -45,6 +45,7 @@
 #include "thread.h"
 #include "request.h"
 #include "user.h"
+#include "security.h"
 
 
 /* thread queues */
@@ -314,6 +315,8 @@ static void set_thread_info( struct thread *thread,
         if (req->affinity != 1) set_error( STATUS_INVALID_PARAMETER );
         else thread->affinity = req->affinity;
     }
+    if (req->mask & SET_THREAD_INFO_TOKEN)
+        security_set_thread_token( thread, req->token );
 }
 
 /* stop a thread (at the Unix level) */
diff --git a/server/token.c b/server/token.c
index f1fba3b27ca..c9ec0cebfdf 100644
--- a/server/token.c
+++ b/server/token.c
@@ -140,6 +140,29 @@ static inline int security_equal_sid( const SID *sid1, const SID *sid2 )
         !memcmp( sid1, sid2, FIELD_OFFSET(SID, SubAuthority[sid1->SubAuthorityCount]) ));
 }
 
+void security_set_thread_token( struct thread *thread, obj_handle_t handle )
+{
+    if (!handle)
+    {
+        if (thread->token)
+            release_object( thread->token );
+        thread->token = NULL;
+    }
+    else
+    {
+        struct token *token = (struct token *)get_handle_obj( current->process,
+                                                              handle,
+                                                              TOKEN_IMPERSONATE,
+                                                              &token_ops );
+        if (token)
+        {
+            if (thread->token)
+                release_object( thread->token );
+            thread->token = token;
+        }
+    }
+}
+
 static const ACE_HEADER *ace_next( const ACE_HEADER *ace )
 {
     return (const ACE_HEADER *)((const char *)ace + ace->AceSize);
@@ -964,8 +987,13 @@ DECL_HANDLER(access_check)
 
         memset(&priv, 0, sizeof(priv));
 
-        /* FIXME: check token is an impersonation token, if not return
-         * STATUS_NO_IMPERSONATION_TOKEN */
+        /* only impersonation tokens may be used with this function */
+        if (token->primary)
+        {
+            set_error( STATUS_NO_IMPERSONATION_TOKEN );
+            release_object( token );
+            return;
+        }
 
         mapping.GenericRead = req->mapping_read;
         mapping.GenericWrite = req->mapping_write;
diff --git a/server/trace.c b/server/trace.c
index d4a1eb2926c..1dcfa0633bb 100644
--- a/server/trace.c
+++ b/server/trace.c
@@ -741,7 +741,8 @@ static void dump_set_thread_info_request( const struct set_thread_info_request *
     fprintf( stderr, " handle=%p,", req->handle );
     fprintf( stderr, " mask=%d,", req->mask );
     fprintf( stderr, " priority=%d,", req->priority );
-    fprintf( stderr, " affinity=%d", req->affinity );
+    fprintf( stderr, " affinity=%d,", req->affinity );
+    fprintf( stderr, " token=%p", req->token );
 }
 
 static void dump_get_dll_info_request( const struct get_dll_info_request *req )