diff --git a/lib/gst/clapper/gtk4/gstgtkbasesink.c b/lib/gst/clapper/gtk4/gstgtkbasesink.c
index 1f35a9de..95e1871f 100644
--- a/lib/gst/clapper/gtk4/gstgtkbasesink.c
+++ b/lib/gst/clapper/gtk4/gstgtkbasesink.c
@@ -117,14 +117,6 @@ gst_gtk_base_sink_class_init (GstGtkBaseSinkClass * klass)
           "The pixel aspect ratio of the device", DEFAULT_PAR_N, DEFAULT_PAR_D,
           G_MAXINT, 1, 1, 1, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
-  /* Disabling alpha was removed in GTK4 */
-#if !defined(BUILD_FOR_GTK4)
-  g_object_class_install_property (gobject_class, PROP_IGNORE_ALPHA,
-      g_param_spec_boolean ("ignore-alpha", "Ignore Alpha",
-          "When enabled, alpha will be ignored and converted to black",
-          DEFAULT_IGNORE_ALPHA, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
-#endif
-
   g_object_class_install_property (gobject_class, PROP_IGNORE_TEXTURES,
       g_param_spec_boolean ("ignore-textures", "Ignore Textures",
           "When enabled, textures will be ignored and not drawn",
@@ -204,11 +196,7 @@ gst_gtk_base_sink_get_widget (GstGtkBaseSink * gtk_sink)
 
   /* Ensure GTK is initialized, this has no side effect if it was already
    * initialized. Also, we do that lazily, so the application can be first */
-  if (!gtk_init_check (
-#if !defined(BUILD_FOR_GTK4)
-          NULL, NULL
-#endif
-      )) {
+  if (!gtk_init_check ()) {
     GST_ERROR_OBJECT (gtk_sink, "Could not ensure GTK initialization.");
     return NULL;
   }
@@ -223,12 +211,6 @@ gst_gtk_base_sink_get_widget (GstGtkBaseSink * gtk_sink)
   gtk_sink->bind_pixel_aspect_ratio =
       g_object_bind_property (gtk_sink, "pixel-aspect-ratio", gtk_sink->widget,
       "pixel-aspect-ratio", G_BINDING_BIDIRECTIONAL | G_BINDING_SYNC_CREATE);
-#if !defined(BUILD_FOR_GTK4)
-  gtk_sink->bind_ignore_alpha =
-      g_object_bind_property (gtk_sink, "ignore-alpha", gtk_sink->widget,
-      "ignore-alpha", G_BINDING_BIDIRECTIONAL | G_BINDING_SYNC_CREATE);
-#endif
-
   gtk_sink->bind_ignore_textures =
       g_object_bind_property (gtk_sink, "ignore-textures", gtk_sink->widget,
       "ignore-textures", G_BINDING_BIDIRECTIONAL | G_BINDING_SYNC_CREATE);
@@ -352,16 +334,13 @@ gst_gtk_base_sink_start_on_main (GstBaseSink * bsink)
   GstGtkBaseSink *gst_sink = GST_GTK_BASE_SINK (bsink);
   GstGtkBaseSinkClass *klass = GST_GTK_BASE_SINK_GET_CLASS (bsink);
   GtkWidget *toplevel;
-#if defined(BUILD_FOR_GTK4)
   GtkRoot *root;
-#endif
 
   if (gst_gtk_base_sink_get_widget (gst_sink) == NULL)
     return FALSE;
 
   /* After this point, gtk_sink->widget will always be set */
 
-#if defined(BUILD_FOR_GTK4)
   root = gtk_widget_get_root (GTK_WIDGET (gst_sink->widget));
   if (!GTK_IS_ROOT (root)) {
     GtkWidget *parent = gtk_widget_get_parent (GTK_WIDGET (gst_sink->widget));
@@ -371,35 +350,19 @@ gst_gtk_base_sink_start_on_main (GstBaseSink * bsink)
         parent = temp_parent;
     }
     toplevel = (parent) ? parent : GTK_WIDGET (gst_sink->widget);
-#else
-  toplevel = gtk_widget_get_toplevel (GTK_WIDGET (gst_sink->widget));
-  if (!gtk_widget_is_toplevel (toplevel)) {
-#endif
+
     /* sanity check */
     g_assert (klass->window_title);
 
     /* User did not add widget its own UI, let's popup a new GtkWindow to
      * make gst-launch-1.0 work. */
-    gst_sink->window = gtk_window_new (
-#if !defined(BUILD_FOR_GTK4)
-        GTK_WINDOW_TOPLEVEL
-#endif
-        );
+    gst_sink->window = gtk_window_new ();
     gtk_window_set_default_size (GTK_WINDOW (gst_sink->window), 640, 480);
     gtk_window_set_title (GTK_WINDOW (gst_sink->window), klass->window_title);
-#if defined(BUILD_FOR_GTK4)
-    gtk_window_set_child (GTK_WINDOW (
-#else
-    gtk_container_add (GTK_CONTAINER (
-#endif
-            gst_sink->window), toplevel);
+    gtk_window_set_child (GTK_WINDOW (gst_sink->window), toplevel);
 
     gst_sink->window_destroy_id = g_signal_connect (
-#if defined(BUILD_FOR_GTK4)
         GTK_WINDOW (gst_sink->window),
-#else
-        gst_sink->window,
-#endif
         "destroy", G_CALLBACK (window_destroy_cb), gst_sink);
   }
 
@@ -419,11 +382,7 @@ gst_gtk_base_sink_stop_on_main (GstBaseSink * bsink)
   GstGtkBaseSink *gst_sink = GST_GTK_BASE_SINK (bsink);
 
   if (gst_sink->window) {
-#if defined(BUILD_FOR_GTK4)
     gtk_window_destroy (GTK_WINDOW (gst_sink->window));
-#else
-    gtk_widget_destroy (gst_sink->window);
-#endif
     gst_sink->window = NULL;
     gst_sink->widget = NULL;
   }
@@ -446,11 +405,7 @@ gst_gtk_base_sink_stop (GstBaseSink * bsink)
 static void
 gst_gtk_window_show_all_and_unref (GtkWidget * window)
 {
-#if defined(BUILD_FOR_GTK4)
   gtk_window_present (GTK_WINDOW (window));
-#else
-  gtk_widget_show_all (window);
-#endif
   g_object_unref (window);
 }
 
diff --git a/lib/gst/clapper/gtk4/gtkconfig.h b/lib/gst/clapper/gtk4/gtkconfig.h
index ecbf9558..76ee9d11 100644
--- a/lib/gst/clapper/gtk4/gtkconfig.h
+++ b/lib/gst/clapper/gtk4/gtkconfig.h
@@ -18,14 +18,7 @@
  * Boston, MA 02110-1301, USA.
  */
 
-#if defined(BUILD_FOR_GTK4)
 #define GTKCONFIG_PLUGIN gtk4
 #define GTKCONFIG_NAME "GTK4"
 #define GTKCONFIG_SINK "gtk4sink"
 #define GTKCONFIG_GLSINK "gtk4glsink"
-#else
-#define GTKCONFIG_PLUGIN gtk
-#define GTKCONFIG_NAME "GTK"
-#define GTKCONFIG_SINK "gtksink"
-#define GTKCONFIG_GLSINK "gtkglsink"
-#endif
diff --git a/lib/gst/clapper/gtk4/gtkgstbasewidget.c b/lib/gst/clapper/gtk4/gtkgstbasewidget.c
index 5ed70f3c..6a1079b6 100644
--- a/lib/gst/clapper/gtk4/gtkgstbasewidget.c
+++ b/lib/gst/clapper/gtk4/gtkgstbasewidget.c
@@ -77,7 +77,6 @@ gtk_gst_base_widget_get_preferred_height (GtkWidget * widget, gint * min,
     *natural = video_height;
 }
 
-#if defined(BUILD_FOR_GTK4)
 static void
 gtk_gst_base_widget_measure (GtkWidget * widget, GtkOrientation orientation,
     gint for_size, gint * min, gint * natural,
@@ -108,7 +107,6 @@ gtk_gst_base_widget_size_allocate (GtkWidget * widget,
 
   gtk_gl_area_queue_render (GTK_GL_AREA (widget));
 }
-#endif
 
 static void
 gtk_gst_base_widget_set_property (GObject * object, guint prop_id,
@@ -276,25 +274,6 @@ _gdk_key_to_navigation_string (guint keyval)
   }
 }
 
-static GdkEvent *
-_get_current_event (GtkEventController * controller)
-{
-#if defined(BUILD_FOR_GTK4)
-  return gtk_event_controller_get_current_event (controller);
-#else
-  return gtk_get_current_event ();
-#endif
-}
-
-static void
-_gdk_event_free (GdkEvent * event)
-{
-#if !defined(BUILD_FOR_GTK4)
-  if (event)
-    gdk_event_free (event);
-#endif
-}
-
 static gboolean
 gtk_gst_base_widget_key_event (GtkEventControllerKey * key_controller,
     guint keyval, guint keycode, GdkModifierType state)
@@ -306,7 +285,7 @@ gtk_gst_base_widget_key_event (GtkEventControllerKey * key_controller,
 
   if ((element = g_weak_ref_get (&base_widget->element))) {
     if (GST_IS_NAVIGATION (element)) {
-      GdkEvent *event = _get_current_event (controller);
+      GdkEvent *event = gtk_event_controller_get_current_event (controller);
       const gchar *str = _gdk_key_to_navigation_string (keyval);
 
       if (str) {
@@ -315,7 +294,6 @@ gtk_gst_base_widget_key_event (GtkEventControllerKey * key_controller,
             GDK_KEY_PRESS ? "key-press" : "key-release";
         gst_navigation_send_key_event (GST_NAVIGATION (element), key_type, str);
       }
-      _gdk_event_free (event);
     }
     g_object_unref (element);
   }
@@ -387,12 +365,7 @@ _display_size_to_stream_size (GtkGstBaseWidget * base_widget, gdouble x,
 }
 
 static gboolean
-gtk_gst_base_widget_button_event (
-#if defined(BUILD_FOR_GTK4)
-    GtkGestureClick * gesture,
-#else
-    GtkGestureMultiPress * gesture,
-#endif
+gtk_gst_base_widget_button_event (GtkGestureClick * gesture,
     gint n_press, gdouble x, gdouble y)
 {
   GtkEventController *controller = GTK_EVENT_CONTROLLER (gesture);
@@ -402,28 +375,18 @@ gtk_gst_base_widget_button_event (
 
   if ((element = g_weak_ref_get (&base_widget->element))) {
     if (GST_IS_NAVIGATION (element)) {
-      GdkEvent *event = _get_current_event (controller);
+      GdkEvent *event = gtk_event_controller_get_current_event (controller);
       const gchar *key_type =
           gdk_event_get_event_type (event) == GDK_BUTTON_PRESS
           ? "mouse-button-press" : "mouse-button-release";
       gdouble stream_x, stream_y;
-#if !defined(BUILD_FOR_GTK4)
-      guint button;
-      gdk_event_get_button (event, &button);
-#endif
 
       _display_size_to_stream_size (base_widget, x, y, &stream_x, &stream_y);
 
       gst_navigation_send_mouse_event (GST_NAVIGATION (element), key_type,
-#if defined(BUILD_FOR_GTK4)
           /* Gesture is set to ignore other buttons so we do not have to check */
           GDK_BUTTON_PRIMARY,
-#else
-          button,
-#endif
           stream_x, stream_y);
-
-      _gdk_event_free (event);
     }
     g_object_unref (element);
   }
@@ -486,13 +449,8 @@ gtk_gst_base_widget_class_init (GtkGstBaseWidgetClass * klass)
           "When enabled, textures will be ignored and not drawn",
           DEFAULT_IGNORE_TEXTURES, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
 
-#if defined(BUILD_FOR_GTK4)
   widget_klass->measure = gtk_gst_base_widget_measure;
   widget_klass->size_allocate = gtk_gst_base_widget_size_allocate;
-#else
-  widget_klass->get_preferred_width = gtk_gst_base_widget_get_preferred_width;
-  widget_klass->get_preferred_height = gtk_gst_base_widget_get_preferred_height;
-#endif
 
   GST_DEBUG_CATEGORY_INIT (gst_debug_gtk_base_widget, "gtkbasewidget", 0,
       "GTK Video Base Widget");
@@ -513,36 +471,22 @@ gtk_gst_base_widget_init (GtkGstBaseWidget * widget)
   g_weak_ref_init (&widget->element, NULL);
   g_mutex_init (&widget->lock);
 
-  widget->key_controller = gtk_event_controller_key_new (
-#if !defined(BUILD_FOR_GTK4)
-      GTK_WIDGET (widget)
-#endif
-      );
+  widget->key_controller = gtk_event_controller_key_new ();
   g_signal_connect (widget->key_controller, "key-pressed",
       G_CALLBACK (gtk_gst_base_widget_key_event), NULL);
   g_signal_connect (widget->key_controller, "key-released",
       G_CALLBACK (gtk_gst_base_widget_key_event), NULL);
 
-  widget->motion_controller = gtk_event_controller_motion_new (
-#if !defined(BUILD_FOR_GTK4)
-      GTK_WIDGET (widget)
-#endif
-      );
+  widget->motion_controller = gtk_event_controller_motion_new ();
   g_signal_connect (widget->motion_controller, "motion",
       G_CALLBACK (gtk_gst_base_widget_motion_event), NULL);
 
-  widget->click_gesture =
-#if defined(BUILD_FOR_GTK4)
-      gtk_gesture_click_new ();
-#else
-      gtk_gesture_multi_press_new (GTK_WIDGET (widget));
-#endif
+  widget->click_gesture = gtk_gesture_click_new ();
   g_signal_connect (widget->click_gesture, "pressed",
       G_CALLBACK (gtk_gst_base_widget_button_event), NULL);
   g_signal_connect (widget->click_gesture, "released",
       G_CALLBACK (gtk_gst_base_widget_button_event), NULL);
 
-#if defined(BUILD_FOR_GTK4)
   /* Otherwise widget in grid will appear as a 1x1px
    * video which might be misleading for users */
   gtk_widget_set_hexpand (GTK_WIDGET (widget), TRUE);
@@ -556,7 +500,6 @@ gtk_gst_base_widget_init (GtkGstBaseWidget * widget)
   gtk_widget_add_controller (GTK_WIDGET (widget), widget->motion_controller);
   gtk_widget_add_controller (GTK_WIDGET (widget),
       GTK_EVENT_CONTROLLER (widget->click_gesture));
-#endif
 
   gtk_widget_set_can_focus (GTK_WIDGET (widget), TRUE);
 }
@@ -566,14 +509,6 @@ gtk_gst_base_widget_finalize (GObject * object)
 {
   GtkGstBaseWidget *widget = GTK_GST_BASE_WIDGET (object);
 
-  /* GTK4 takes ownership of EventControllers
-   * while GTK3 still needs manual unref */
-#if !defined(BUILD_FOR_GTK4)
-  g_object_unref (widget->key_controller);
-  g_object_unref (widget->motion_controller);
-  g_object_unref (widget->click_gesture);
-#endif
-
   gst_buffer_replace (&widget->pending_buffer, NULL);
   gst_buffer_replace (&widget->buffer, NULL);
   g_mutex_clear (&widget->lock);
diff --git a/lib/gst/clapper/gtk4/gtkgstbasewidget.h b/lib/gst/clapper/gtk4/gtkgstbasewidget.h
index a8e899b2..4532b821 100644
--- a/lib/gst/clapper/gtk4/gtkgstbasewidget.h
+++ b/lib/gst/clapper/gtk4/gtkgstbasewidget.h
@@ -26,10 +26,6 @@
 #include <gst/gst.h>
 #include <gst/video/video.h>
 
-#if !defined(BUILD_FOR_GTK4)
-#include <gdk/gdk.h>
-#endif
-
 #define GTK_GST_BASE_WIDGET(w)         ((GtkGstBaseWidget *)(w))
 #define GTK_GST_BASE_WIDGET_CLASS(k)   ((GtkGstBaseWidgetClass *)(k))
 #define GTK_GST_BASE_WIDGET_LOCK(w)    g_mutex_lock(&((GtkGstBaseWidget*)(w))->lock)
diff --git a/lib/gst/clapper/gtk4/gtkgstglwidget.c b/lib/gst/clapper/gtk4/gtkgstglwidget.c
index 2903fb0b..6b3ee8df 100644
--- a/lib/gst/clapper/gtk4/gtkgstglwidget.c
+++ b/lib/gst/clapper/gtk4/gtkgstglwidget.c
@@ -31,20 +31,12 @@
 #include <gst/video/video.h>
 
 #if GST_GL_HAVE_WINDOW_X11 && defined (GDK_WINDOWING_X11)
-#if defined(BUILD_FOR_GTK4)
 #include <gdk/x11/gdkx.h>
-#else
-#include <gdk/gdkx.h>
-#endif
 #include <gst/gl/x11/gstgldisplay_x11.h>
 #endif
 
 #if GST_GL_HAVE_WINDOW_WAYLAND && defined (GDK_WINDOWING_WAYLAND)
-#if defined(BUILD_FOR_GTK4)
 #include <gdk/wayland/gdkwayland.h>
-#else
-#include <gdk/gdkwayland.h>
-#endif
 #include <gst/gl/wayland/gstgldisplay_wayland.h>
 #endif
 
@@ -419,12 +411,6 @@ gtk_gst_gl_widget_init (GtkGstGLWidget * gst_widget)
 
   GST_INFO ("Created %" GST_PTR_FORMAT, priv->display);
 
-  /* GTK4 always has alpha */
-#if !defined(BUILD_FOR_GTK4)
-  gtk_gl_area_set_has_alpha (GTK_GL_AREA (gst_widget),
-      !base_widget->ignore_alpha);
-#endif
-
   gtk_gl_area_set_auto_render (GTK_GL_AREA (gst_widget), FALSE);
 }
 
diff --git a/lib/gst/clapper/meson.build b/lib/gst/clapper/meson.build
index 961d2f14..456706d8 100644
--- a/lib/gst/clapper/meson.build
+++ b/lib/gst/clapper/meson.build
@@ -32,7 +32,6 @@ gstclapper_defines = [
   '-DBUILDING_GST_CLAPPER',
   '-DGST_USE_UNSTABLE_API',
   '-DHAVE_GTK_GL',
-  '-DBUILD_FOR_GTK4',
 ]
 gtk_deps = [gstgl_dep, gstglproto_dep]
 have_gtk_gl_windowing = false