diff --git a/gui-libs/gtk/gtk-4.18.6-r1.ebuild b/gui-libs/gtk/gtk-4.18.6-r1.ebuild
index 9fb5726b7cd51..2b7450b95058b 100644
--- a/gui-libs/gtk/gtk-4.18.6-r1.ebuild
+++ b/gui-libs/gtk/gtk-4.18.6-r1.ebuild
@@ -3,7 +3,7 @@
 
 EAPI=8
 PYTHON_COMPAT=( python3_{11..14} )
-inherit gnome.org gnome2-utils meson optfeature python-any-r1 toolchain-funcs virtualx xdg
+inherit flag-o-matic gnome.org gnome2-utils meson optfeature python-any-r1 toolchain-funcs virtualx xdg
 
 DESCRIPTION="GTK is a multi-platform toolkit for creating graphical user interfaces"
 HOMEPAGE="https://www.gtk.org/ https://gitlab.gnome.org/GNOME/gtk/"
@@ -148,6 +148,8 @@ src_prepare() {
 }
 
 src_configure() {
+	use x86 && append-flags -DDISABLE_X64=1 #943705 https://gitlab.gnome.org/GNOME/gtk/-/issues/4173
+
 	local emesonargs=(
 		# GDK backends
 		$(meson_use X x11-backend)
diff --git a/gui-libs/gtk/gtk-4.20.1.ebuild b/gui-libs/gtk/gtk-4.20.1.ebuild
index 216584e772c6b..5095297ab9a8b 100644
--- a/gui-libs/gtk/gtk-4.20.1.ebuild
+++ b/gui-libs/gtk/gtk-4.20.1.ebuild
@@ -3,7 +3,7 @@
 
 EAPI=8
 PYTHON_COMPAT=( python3_{11..14} )
-inherit gnome.org gnome2-utils meson optfeature python-any-r1 toolchain-funcs virtualx xdg
+inherit flag-o-matic gnome.org gnome2-utils meson optfeature python-any-r1 toolchain-funcs virtualx xdg
 
 DESCRIPTION="GTK is a multi-platform toolkit for creating graphical user interfaces"
 HOMEPAGE="https://www.gtk.org/ https://gitlab.gnome.org/GNOME/gtk/"
@@ -150,6 +150,8 @@ src_prepare() {
 }
 
 src_configure() {
+	use x86 && append-flags -DDISABLE_X64=1 #943705 https://gitlab.gnome.org/GNOME/gtk/-/issues/4173
+
 	local emesonargs=(
 		# GDK backends
 		$(meson_use X x11-backend)
diff --git a/gui-libs/gtk/gtk-4.20.2.ebuild b/gui-libs/gtk/gtk-4.20.2.ebuild
index 216584e772c6b..5095297ab9a8b 100644
--- a/gui-libs/gtk/gtk-4.20.2.ebuild
+++ b/gui-libs/gtk/gtk-4.20.2.ebuild
@@ -3,7 +3,7 @@
 
 EAPI=8
 PYTHON_COMPAT=( python3_{11..14} )
-inherit gnome.org gnome2-utils meson optfeature python-any-r1 toolchain-funcs virtualx xdg
+inherit flag-o-matic gnome.org gnome2-utils meson optfeature python-any-r1 toolchain-funcs virtualx xdg
 
 DESCRIPTION="GTK is a multi-platform toolkit for creating graphical user interfaces"
 HOMEPAGE="https://www.gtk.org/ https://gitlab.gnome.org/GNOME/gtk/"
@@ -150,6 +150,8 @@ src_prepare() {
 }
 
 src_configure() {
+	use x86 && append-flags -DDISABLE_X64=1 #943705 https://gitlab.gnome.org/GNOME/gtk/-/issues/4173
+
 	local emesonargs=(
 		# GDK backends
 		$(meson_use X x11-backend)