diff --git a/src/calendar.c b/src/calendar.c
index c62c181..c0f7af1 100644
--- a/src/calendar.c
+++ b/src/calendar.c
@@ -67,6 +67,9 @@ zenity_calendar (ZenityData *data, ZenityCalendarData *cal_data)
   if (data->width > -1 || data->height > -1)
     gtk_window_set_default_size (GTK_WINDOW (dialog), data->width, data->height);
 
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+
   text = gtk_builder_get_object (builder, "zenity_calendar_text");
 
   if (cal_data->dialog_text)
diff --git a/src/color.c b/src/color.c
index 4c9c151..791d76d 100644
--- a/src/color.c
+++ b/src/color.c
@@ -73,6 +73,9 @@ void zenity_colorselection (ZenityData *data, ZenityColorData *color_data)
     g_object_unref (G_OBJECT (button));
   }
 
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+
   gtk_color_selection_set_has_palette (GTK_COLOR_SELECTION (colorsel),
                                        color_data->show_palette);
 
diff --git a/src/entry.c b/src/entry.c
index 2b92e59..72f73b5 100644
--- a/src/entry.c
+++ b/src/entry.c
@@ -80,6 +80,9 @@ zenity_entry (ZenityData *data, ZenityEntryData *entry_data)
 
   if (data->width > -1 || data->height > -1)
     gtk_window_set_default_size (GTK_WINDOW (dialog), data->width, data->height);
+
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
   
   if (data->ok_label) {
     button = GTK_WIDGET (gtk_builder_get_object (builder, "zenity_entry_ok_button"));
diff --git a/src/fileselection.c b/src/fileselection.c
index 349ff32..cf82f02 100644
--- a/src/fileselection.c
+++ b/src/fileselection.c
@@ -67,6 +67,9 @@ void zenity_fileselection (ZenityData *data, ZenityFileData *file_data)
 	
   zenity_util_set_window_icon (dialog, data->window_icon, ZENITY_IMAGE_FULLPATH ("zenity-file.png"));
 
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+
   if (file_data->uri) {
     dir = g_path_get_dirname (file_data->uri);
 
diff --git a/src/msg.c b/src/msg.c
index 667239b..505f961 100644
--- a/src/msg.c
+++ b/src/msg.c
@@ -142,6 +142,9 @@ zenity_msg (ZenityData *data, ZenityMsgData *msg_data)
   
   if (data->width > -1 || data->height > -1)
     gtk_window_set_default_size (GTK_WINDOW (dialog), data->width, data->height);
+
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
         
   if (msg_data->dialog_text) {
     if (msg_data->no_markup)
diff --git a/src/option.c b/src/option.c
index ee0e9c2..ba4691d 100644
--- a/src/option.c
+++ b/src/option.c
@@ -44,6 +44,7 @@ static gboolean zenity_general_dialog_no_markup;
 static gint     zenity_general_timeout_delay;
 static gchar   *zenity_general_ok_button;
 static gchar   *zenity_general_cancel_button;
+static gboolean zenity_general_modal;
 
 /* Calendar Dialog Options */
 static gboolean zenity_calendar_active;
@@ -210,6 +211,15 @@ static GOptionEntry general_options[] = {
     N_("Sets the label of the Cancel button"),
     N_("TEXT")
   },
+  {
+    "modal",
+    '\0',
+    G_OPTION_FLAG_NOALIAS,
+    G_OPTION_ARG_NONE,
+    &zenity_general_modal,
+    N_("Set the modal hint"),
+    NULL
+  },
   {
     NULL
   }
@@ -1287,6 +1297,7 @@ zenity_general_pre_callback (GOptionContext *context,
   zenity_general_dialog_no_wrap = FALSE;
   zenity_general_dialog_no_markup = FALSE;
   zenity_general_timeout_delay = -1;
+  zenity_general_modal = FALSE;
 
   return TRUE;
 }
@@ -1524,6 +1535,7 @@ zenity_general_post_callback (GOptionContext *context,
   results->data->timeout_delay = zenity_general_timeout_delay;
   results->data->ok_label = zenity_general_ok_button;
   results->data->cancel_label = zenity_general_cancel_button;
+  results->data->modal = zenity_general_modal;
   return TRUE;
 }
 
diff --git a/src/password.c b/src/password.c
index b656d8f..1582f95 100644
--- a/src/password.c
+++ b/src/password.c
@@ -134,6 +134,9 @@ void zenity_password_dialog (ZenityData *data, ZenityPasswordData *password_data
   if (data->dialog_title)
     gtk_window_set_title (GTK_WINDOW (dialog), data->dialog_title);
 
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+
   g_signal_connect (G_OBJECT (dialog), "response",
                     G_CALLBACK (zenity_password_dialog_response),
                     password_data);
diff --git a/src/progress.c b/src/progress.c
index 3e6f5a2..fca31c8 100644
--- a/src/progress.c
+++ b/src/progress.c
@@ -259,6 +259,9 @@ zenity_progress (ZenityData *data, ZenityProgressData *progress_data)
   if (data->width > -1 || data->height > -1)
     gtk_window_set_default_size (GTK_WINDOW (dialog), data->width, data->height);
 
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+
   if (data->ok_label) {
     button = GTK_WIDGET (gtk_builder_get_object (builder, "zenity_progress_ok_button"));
     gtk_button_set_label (GTK_BUTTON (button), data->ok_label);
diff --git a/src/scale.c b/src/scale.c
index 11d9588..21f820e 100644
--- a/src/scale.c
+++ b/src/scale.c
@@ -75,6 +75,9 @@ zenity_scale (ZenityData *data, ZenityScaleData *scale_data)
   
   if (data->width > -1 || data->height > -1)
     gtk_window_set_default_size (GTK_WINDOW (dialog), data->width, data->height);
+
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
         
   if (data->ok_label) {
     button = GTK_WIDGET (gtk_builder_get_object (builder, "zenity_scale_ok_button"));
diff --git a/src/text.c b/src/text.c
index 9c031cb..0163c3c 100644
--- a/src/text.c
+++ b/src/text.c
@@ -288,6 +288,9 @@ zenity_text (ZenityData *data, ZenityTextData *text_data)
   else
     gtk_window_set_default_size (GTK_WINDOW (dialog), 300, 400); 
 
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+
 #ifdef HAVE_WEBKITGTK
   if(text_data->html) {
     web_kit = webkit_web_view_new();
diff --git a/src/tree.c b/src/tree.c
index 4234fc1..c1a20d0 100644
--- a/src/tree.c
+++ b/src/tree.c
@@ -383,6 +383,9 @@ zenity_tree (ZenityData *data, ZenityTreeData *tree_data)
   if (data->dialog_title)
     gtk_window_set_title (GTK_WINDOW (dialog), data->dialog_title);
 
+  if (data->modal)
+    gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);
+
   if (data->ok_label) {
     button = GTK_WIDGET (gtk_builder_get_object (builder, "zenity_tree_ok_button"));
     gtk_button_set_label (GTK_BUTTON (button), data->ok_label);
diff --git a/src/zenity.h b/src/zenity.h
index 30c497b..2eec3aa 100644
--- a/src/zenity.h
+++ b/src/zenity.h
@@ -32,6 +32,7 @@ typedef struct {
   gint   height;
   gint   exit_code;
   gint   timeout_delay;
+  gboolean modal;
 } ZenityData;
 
 typedef enum {