diff --git a/dlls/ntdll/unix/server.c b/dlls/ntdll/unix/server.c
index fe57b622f94..5348b07fe13 100644
--- a/dlls/ntdll/unix/server.c
+++ b/dlls/ntdll/unix/server.c
@@ -691,10 +691,15 @@ unsigned int server_select( const select_op_t *select_op, data_size_t size, UINT
     int cookie;
     obj_handle_t apc_handle = 0;
     BOOL suspend_context = !!context;
-    apc_call_t call;
     apc_result_t result;
     sigset_t old_set;
     int signaled;
+    data_size_t reply_size;
+    struct
+    {
+        apc_call_t call;
+        context_t  context[2];
+    } reply_data;
 
     memset( &result, 0, sizeof(result) );
 
@@ -718,16 +723,17 @@ unsigned int server_select( const select_op_t *select_op, data_size_t size, UINT
                     wine_server_add_data( req, context, ctx_size );
                     suspend_context = FALSE; /* server owns the context now */
                 }
-                if (context) wine_server_set_reply( req, context, 2 * sizeof(*context) );
+                wine_server_set_reply( req, &reply_data,
+                                       context ? sizeof(reply_data) : sizeof(reply_data.call) );
                 ret = server_call_unlocked( req );
                 signaled    = reply->signaled;
                 apc_handle  = reply->apc_handle;
-                call        = reply->call;
+                reply_size  = wine_server_reply_size( reply );
             }
             SERVER_END_REQ;
 
             if (ret != STATUS_KERNEL_APC) break;
-            invoke_system_apc( &call, &result, FALSE );
+            invoke_system_apc( &reply_data.call, &result, FALSE );
 
             /* don't signal multiple times */
             if (size >= sizeof(select_op->signal_and_wait) && select_op->op == SELECT_SIGNAL_AND_WAIT)
@@ -740,7 +746,9 @@ unsigned int server_select( const select_op_t *select_op, data_size_t size, UINT
     }
     while (ret == STATUS_USER_APC || ret == STATUS_KERNEL_APC);
 
-    if (ret == STATUS_USER_APC) *user_apc = call.user;
+    if (ret == STATUS_USER_APC) *user_apc = reply_data.call.user;
+    if (reply_size > sizeof(reply_data.call))
+        memcpy( context, reply_data.context, reply_size - sizeof(reply_data.call) );
     return ret;
 }
 
diff --git a/include/wine/server_protocol.h b/include/wine/server_protocol.h
index 340512a054e..5a14a3c4370 100644
--- a/include/wine/server_protocol.h
+++ b/include/wine/server_protocol.h
@@ -1381,9 +1381,9 @@ struct select_request
 struct select_reply
 {
     struct reply_header __header;
-    apc_call_t   call;
     obj_handle_t apc_handle;
     int          signaled;
+    /* VARARG(call,apc_call); */
     /* VARARG(contexts,contexts); */
 };
 #define SELECT_ALERTABLE     1
@@ -6413,7 +6413,7 @@ union generic_reply
 
 /* ### protocol_version begin ### */
 
-#define SERVER_PROTOCOL_VERSION 773
+#define SERVER_PROTOCOL_VERSION 774
 
 /* ### protocol_version end ### */
 
diff --git a/server/protocol.def b/server/protocol.def
index 7995f481e19..4237737ab40 100644
--- a/server/protocol.def
+++ b/server/protocol.def
@@ -1221,9 +1221,9 @@ typedef struct
     VARARG(data,select_op,size); /* operation-specific data */
     VARARG(contexts,contexts);   /* suspend context(s) */
 @REPLY
-    apc_call_t   call;         /* APC call arguments */
     obj_handle_t apc_handle;   /* handle to next APC */
     int          signaled;     /* were the handles immediately signaled? */
+    VARARG(call,apc_call);     /* APC call arguments */
     VARARG(contexts,contexts); /* suspend context(s) */
 @END
 #define SELECT_ALERTABLE     1
diff --git a/server/request.h b/server/request.h
index b13381d3fe1..ea08babdda8 100644
--- a/server/request.h
+++ b/server/request.h
@@ -689,7 +689,6 @@ static const req_handler req_handlers[REQ_NB_REQUESTS] =
 
 C_ASSERT( sizeof(abstime_t) == 8 );
 C_ASSERT( sizeof(affinity_t) == 8 );
-C_ASSERT( sizeof(apc_call_t) == 48 );
 C_ASSERT( sizeof(apc_param_t) == 8 );
 C_ASSERT( sizeof(apc_result_t) == 40 );
 C_ASSERT( sizeof(async_data_t) == 40 );
@@ -909,10 +908,9 @@ C_ASSERT( FIELD_OFFSET(struct select_request, timeout) == 24 );
 C_ASSERT( FIELD_OFFSET(struct select_request, size) == 32 );
 C_ASSERT( FIELD_OFFSET(struct select_request, prev_apc) == 36 );
 C_ASSERT( sizeof(struct select_request) == 40 );
-C_ASSERT( FIELD_OFFSET(struct select_reply, call) == 8 );
-C_ASSERT( FIELD_OFFSET(struct select_reply, apc_handle) == 56 );
-C_ASSERT( FIELD_OFFSET(struct select_reply, signaled) == 60 );
-C_ASSERT( sizeof(struct select_reply) == 64 );
+C_ASSERT( FIELD_OFFSET(struct select_reply, apc_handle) == 8 );
+C_ASSERT( FIELD_OFFSET(struct select_reply, signaled) == 12 );
+C_ASSERT( sizeof(struct select_reply) == 16 );
 C_ASSERT( FIELD_OFFSET(struct create_event_request, access) == 12 );
 C_ASSERT( FIELD_OFFSET(struct create_event_request, manual_reset) == 16 );
 C_ASSERT( FIELD_OFFSET(struct create_event_request, initial_state) == 20 );
diff --git a/server/thread.c b/server/thread.c
index 5299f6c042d..3e35b27f694 100644
--- a/server/thread.c
+++ b/server/thread.c
@@ -1658,17 +1658,19 @@ DECL_HANDLER(select)
 
     reply->signaled = select_on( &select_op, op_size, req->cookie, req->flags, req->timeout );
 
-    if (get_error() == STATUS_USER_APC)
+    if (get_error() == STATUS_USER_APC && get_reply_max_size() >= sizeof(apc_call_t))
     {
         apc = thread_dequeue_apc( current, 0 );
-        reply->call = apc->call;
+        set_reply_data( &apc->call, sizeof(apc->call) );
         release_object( apc );
     }
-    else if (get_error() == STATUS_KERNEL_APC)
+    else if (get_error() == STATUS_KERNEL_APC && get_reply_max_size() >= sizeof(apc_call_t))
     {
         apc = thread_dequeue_apc( current, 1 );
         if ((reply->apc_handle = alloc_handle( current->process, apc, SYNCHRONIZE, 0 )))
-            reply->call = apc->call;
+        {
+            set_reply_data( &apc->call, sizeof(apc->call) );
+        }
         else
         {
             apc->executed = 1;
@@ -1676,16 +1678,23 @@ DECL_HANDLER(select)
         }
         release_object( apc );
     }
-    else if (reply->signaled && get_reply_max_size() >= sizeof(context_t) &&
+    else if (reply->signaled && get_reply_max_size() >= sizeof(apc_call_t) + sizeof(context_t) &&
              current->context && current->suspend_cookie == req->cookie)
     {
         ctx = current->context;
         if (ctx->regs[CTX_NATIVE].flags || ctx->regs[CTX_WOW].flags)
         {
-            data_size_t size = (ctx->regs[CTX_WOW].flags ? 2 : 1) * sizeof(context_t);
+            apc_call_t *data;
+            data_size_t size = sizeof(*data) + (ctx->regs[CTX_WOW].flags ? 2 : 1) * sizeof(context_t);
             unsigned int flags = system_flags & ctx->regs[CTX_NATIVE].flags;
+
             if (flags) set_thread_context( current, &ctx->regs[CTX_NATIVE], flags );
-            set_reply_data( ctx->regs, min( size, get_reply_max_size() ));
+            size = min( size, get_reply_max_size() );
+            if ((data = set_reply_data_size( size )))
+            {
+                memset( data, 0, sizeof(*data) );
+                memcpy( data + 1, ctx->regs, size - sizeof(*data) );
+            }
         }
         release_object( ctx );
         current->context = NULL;
diff --git a/server/trace.c b/server/trace.c
index 7cd6f8938d3..96b8992f351 100644
--- a/server/trace.c
+++ b/server/trace.c
@@ -1752,9 +1752,9 @@ static void dump_select_request( const struct select_request *req )
 
 static void dump_select_reply( const struct select_reply *req )
 {
-    dump_apc_call( " call=", &req->call );
-    fprintf( stderr, ", apc_handle=%04x", req->apc_handle );
+    fprintf( stderr, " apc_handle=%04x", req->apc_handle );
     fprintf( stderr, ", signaled=%d", req->signaled );
+    dump_varargs_apc_call( ", call=", cur_size );
     dump_varargs_contexts( ", contexts=", cur_size );
 }
 
diff --git a/tools/make_requests b/tools/make_requests
index 158b2006ae5..e5db1c7fc0a 100755
--- a/tools/make_requests
+++ b/tools/make_requests
@@ -45,7 +45,6 @@ my %formats =
     "timeout_t"     => [  8,   8,  "&dump_timeout" ],
     "abstime_t"     => [  8,   8,  "&dump_abstime" ],
     "rectangle_t"   => [  16,  4,  "&dump_rectangle" ],
-    "apc_call_t"    => [  48,  8,  "&dump_apc_call" ],
     "apc_result_t"  => [  40,  8,  "&dump_apc_result" ],
     "async_data_t"  => [  40,  8,  "&dump_async_data" ],
     "irp_params_t"  => [  32,  8,  "&dump_irp_params" ],