diff --git a/build/cmake/modules/FindGTK3.cmake b/build/cmake/modules/FindGTK3.cmake
index 5c35029a81..8fee6f9f41 100644
--- a/build/cmake/modules/FindGTK3.cmake
+++ b/build/cmake/modules/FindGTK3.cmake
@@ -46,5 +46,6 @@ endif ()
 include(CheckSymbolExists)
 set(CMAKE_REQUIRED_INCLUDES ${GTK3_INCLUDE_DIRS})
 check_symbol_exists(GDK_WINDOWING_WAYLAND "gdk/gdk.h" wxHAVE_GDK_WAYLAND)
+check_symbol_exists(GDK_WINDOWING_X11 "gdk/gdk.h" wxHAVE_GDK_X11)
 include(FindPackageHandleStandardArgs)
 FIND_PACKAGE_HANDLE_STANDARD_ARGS(GTK3 DEFAULT_MSG GTK3_INCLUDE_DIRS GTK3_LIBRARIES VERSION_OK)
diff --git a/build/cmake/toolkit.cmake b/build/cmake/toolkit.cmake
index 577d3c8661..bcbbd75491 100644
--- a/build/cmake/toolkit.cmake
+++ b/build/cmake/toolkit.cmake
@@ -69,12 +69,6 @@ set(wxTOOLKIT_INCLUDE_DIRS)
 set(wxTOOLKIT_LIBRARIES)
 set(wxTOOLKIT_VERSION)
 
-if(UNIX AND NOT APPLE AND NOT WIN32)
-    find_package(X11 REQUIRED)
-    list(APPEND wxTOOLKIT_INCLUDE_DIRS ${X11_INCLUDE_DIR})
-    list(APPEND wxTOOLKIT_LIBRARIES ${X11_LIBRARIES})
-endif()
-
 if(WXGTK)
     if(WXGTK4)
         set(gtk_lib GTK4)
@@ -121,6 +115,15 @@ if(WXGTK)
     endif()
 endif()
 
+# We need X11 for non-GTK Unix ports (X11, Motif) and for GTK with X11
+# support, but not for Wayland-only GTK (which is why we have to do this after
+# find_package(GTKx) above, as this is what sets wxHAVE_GDK_X11).
+if(UNIX AND NOT APPLE AND NOT WIN32 AND (WXX11 OR WXMOTIF OR (WXGTK AND wxHAVE_GDK_X11)))
+    find_package(X11 REQUIRED)
+    list(APPEND wxTOOLKIT_INCLUDE_DIRS ${X11_INCLUDE_DIR})
+    list(APPEND wxTOOLKIT_LIBRARIES ${X11_LIBRARIES})
+endif()
+
 if(WXQT)
     set(QT_COMPONENTS Core Widgets Gui OpenGL Test)
     foreach(QT_COMPONENT ${QT_COMPONENTS})
diff --git a/src/unix/utilsx11.cpp b/src/unix/utilsx11.cpp
index aabd8912ca..2b5fa89732 100644
--- a/src/unix/utilsx11.cpp
+++ b/src/unix/utilsx11.cpp
@@ -13,8 +13,6 @@
 // for compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
-#include "wx/unix/utilsx11.h"
-
 #ifndef WX_PRECOMP
     #include "wx/log.h"
     #include "wx/app.h"
@@ -26,16 +24,6 @@
 #include "wx/apptrait.h"
 #include "wx/private/launchbrowser.h"
 
-#ifdef __VMS
-#pragma message disable nosimpint
-#endif
-#include <X11/Xlib.h>
-#include <X11/Xatom.h>
-#include <X11/Xutil.h>
-#ifdef __VMS
-#pragma message enable nosimpint
-#endif
-
 #ifdef __WXGTK__
 #ifdef __WXGTK20__
 #include "wx/gtk/private/wrapgtk.h"
@@ -45,20 +33,31 @@
 #endif
 #ifdef GDK_WINDOWING_X11
 #include <gdk/gdkx.h>
+#define wxHAS_X11_SUPPORT
 #endif
 GdkWindow* wxGetTopLevelGDK();
 GtkWidget* wxGetTopLevelGTK();
-#endif
 
-#ifdef GTK_CHECK_VERSION
 #if GTK_CHECK_VERSION(3,4,0)
 #define wxHAS_GETKEYSTATE_GTK
 #endif //GTK+ 3.4
-#endif
+#else
+// When not using GTK we always use X11, as we don't support anything else.
+#define wxHAS_X11_SUPPORT
+#endif // GTK
 
-// Only X11 backend is supported for wxGTK here (GTK < 2 has no others)
-#if !defined(__WXGTK__) || \
-    (!defined(__WXGTK20__) || defined(GDK_WINDOWING_X11))
+#ifdef wxHAS_X11_SUPPORT
+
+#include "wx/unix/utilsx11.h"
+
+#ifdef __VMS
+#pragma message disable nosimpint
+#endif
+#include <X11/Xatom.h>
+#include <X11/Xutil.h>
+#ifdef __VMS
+#pragma message enable nosimpint
+#endif
 
 // Various X11 Atoms used in this file:
 static Atom _NET_WM_STATE = 0;
@@ -2595,7 +2594,7 @@ static bool wxGetKeyStateX11(wxKeyCode key)
     return (key_vector[keyCode >> 3] & (1 << (keyCode & 7))) != 0;
 }
 
-#endif // !defined(__WXGTK__) || defined(GDK_WINDOWING_X11)
+#endif // wxHAS_X11_SUPPORT
 
 // We need to use GDK functions when using wxGTK with a non-X11 backend, the
 // X11 code above can't work in this case.
@@ -2649,9 +2648,9 @@ bool wxGetKeyState(wxKeyCode key)
     }
 #endif // GTK+ 3.4+
 
-#if !defined(__WXGTK__) ||                                      \
-    (!defined(__WXGTK20__) || defined(GDK_WINDOWING_X11))
-    return wxGetKeyStateX11(key);
+#ifdef wxHAS_X11_SUPPORT
+    if ( wxGetKeyStateX11(key) )
+        return true;
 #endif
 
     return false;