diff --git a/src/Wt/WApplication.C b/src/Wt/WApplication.C
index 2215ca6274..fbc579c190 100755
--- a/src/Wt/WApplication.C
+++ b/src/Wt/WApplication.C
@@ -14,6 +14,7 @@
 #include "Wt/WDate"
 #include "Wt/WDefaultLoadingIndicator"
 #include "Wt/WException"
+#include "Wt/WFileUpload"
 #include "Wt/WMemoryResource"
 #include "Wt/WServer"
 #include "Wt/WTimer"
@@ -517,13 +518,11 @@ void WApplication::removeGlobalWidget(WWidget *)
 
 bool WApplication::isExposed(WWidget *w) const
 {
-  /*
-   * This not right: for example a file upload is usually hidden while
-   * uploading, but then could not receive the upload event
-
-  if (!w->isVisible())
+  // File uploads may be hidden when emitting a signal.
+  // Other hidden widgets should not emit signals.
+  if (!w->isVisible() && !dynamic_cast<WFileUpload*>(w))
     return false;
-  */
+
   if (!w->isEnabled())
     return false;
 
diff --git a/src/web/WebSession.C b/src/web/WebSession.C
index fee2e2f18a..0b8072b39d 100644
--- a/src/web/WebSession.C
+++ b/src/web/WebSession.C
@@ -2850,8 +2850,8 @@ void WebSession::propagateFormValues(const WEvent& e, const std::string& se)
 
     if (!request.postDataExceeded()) {
       WWidget *w = dynamic_cast<WWidget*>(obj);
-      if (w && !w->isEnabled())
-	continue; // Do not update form data of a disabled widget
+      if (w && (!w->isEnabled() || !w->isVisible()))
+	continue; // Do not update form data of a disabled or invisible widget
       obj->setFormData(getFormData(request, se + formName));
     } else
       obj->setRequestTooLarge(request.postDataExceeded());