diff --git a/private/lib/linux/x86_64/librktwebview_qt.so b/private/lib/linux/x86_64/librktwebview_qt.so
index d388aa2..6aaa0b0 100755
Binary files a/private/lib/linux/x86_64/librktwebview_qt.so and b/private/lib/linux/x86_64/librktwebview_qt.so differ
diff --git a/private/racket-webview-qt.rkt b/private/racket-webview-qt.rkt
index fb3be7a..876d1cf 100644
--- a/private/racket-webview-qt.rkt
+++ b/private/racket-webview-qt.rkt
@@ -155,7 +155,8 @@
                                  (libname libn)))
                    )
               ;(displayln (format "loading ~a" load-lib))
-              (ffi-lib load-lib versions)
+              (ffi-lib load-lib versions
+                       ;#:custodian (current-custodian))
               )
             )
           libraries-to-preload)
@@ -180,7 +181,12 @@
                                       ffi-library os exp))))
                      )
                    ])
-    (ffi-lib webview-lib-file '("6" #f) #:get-lib-dirs (list os-lib-dir))))
+    (ffi-lib webview-lib-file '("6" #f)
+             #:get-lib-dirs (list os-lib-dir)
+             ;#:custodian (current-custodian)
+             )
+    )
+  )
 
 (define-ffi-definer define-rktwebview webview-lib)
 
diff --git a/rktwebview_qt/CMakeLists.txt b/rktwebview_qt/CMakeLists.txt
index 6894b03..a934dad 100644
--- a/rktwebview_qt/CMakeLists.txt
+++ b/rktwebview_qt/CMakeLists.txt
@@ -24,6 +24,9 @@ add_library(rktwebview_qt SHARED
 
   rktutils.h rktutils.cpp
   command.h command.cpp
+  shm.h shm.cpp
+  shmqueue.h shmqueue.cpp
+
 )
 
 target_link_libraries(rktwebview_qt PRIVATE Qt${QT_VERSION_MAJOR}::Widgets)
diff --git a/rktwebview_qt/rktwebview.cpp b/rktwebview_qt/rktwebview.cpp
index 9dfa0ae..3877dcf 100644
--- a/rktwebview_qt/rktwebview.cpp
+++ b/rktwebview_qt/rktwebview.cpp
@@ -7,6 +7,7 @@
 //#include <unistd.h>
 #include <fcntl.h>
 #include "rktwebview_qt.h"
+#include "shmqueue.h"
 
 uint64_t current_ms() {
     using namespace std::chrono;
@@ -17,7 +18,14 @@ uint64_t current_ms() {
 // Main C Interface
 /////////////////////////////////////////////////////////////////////
 
-Rktwebview_qt *handler = nullptr;
+typedef struct {
+    Shm *shm;
+    ShmQueue *command_queue;
+    ShmQueue *event_queue;
+    Rktwebview_qt *rkt;
+} Handle_t;
+
+Handle_t *handler = nullptr;
 
 void rkt_webview_cleanup()
 {
@@ -25,6 +33,27 @@ void rkt_webview_cleanup()
         // Does nothing.
         // See QTBUG-145033
         // QtWebEngine cannot be started as part of QApplication more than once in an application run.
+        // So we would need to cleanup at exit of racket/drracket.
+        // Cleaning up when exiting the current custodian is not enough.
+
+        /*
+        QApplication *app = handler->app();
+        if (app != nullptr) {
+            // testing with #:custodian (current-custodian)
+            QTimer t;
+            QObject::connect(&t, &QTimer::timeout, app, [app]() {
+                fprintf(stderr, "Quitting\n");
+                app->quit();
+            });
+            t.setSingleShot(true);
+            t.start(250);
+            fprintf(stderr, "Executing app\n");
+            app->exec();
+            fprintf(stderr, "App exited\n");
+            delete handler;
+            handler = nullptr;
+        }
+        */
     }
 }