diff --git a/accessible/atk/moz.build b/accessible/atk/moz.build
index ce6be5a3faf4..00af8e3eadb3 100644
--- a/accessible/atk/moz.build
+++ b/accessible/atk/moz.build
@@ -50,8 +50,8 @@ LOCAL_INCLUDES += [
 FINAL_LIBRARY = "xul"
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CFLAGS += CONFIG["TK_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 if CONFIG["MOZ_ENABLE_DBUS"]:
     CXXFLAGS += CONFIG["MOZ_DBUS_CFLAGS"]
diff --git a/browser/components/shell/moz.build b/browser/components/shell/moz.build
index a6e5d6606181..ff17e5f35a06 100644
--- a/browser/components/shell/moz.build
+++ b/browser/components/shell/moz.build
@@ -81,9 +81,7 @@ for var in (
 ):
     DEFINES[var] = '"%s"' % CONFIG[var]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 if CONFIG["MOZ_ENABLE_DBUS"]:
     CXXFLAGS += CONFIG["MOZ_DBUS_GLIB_CFLAGS"]
 
diff --git a/chrome/moz.build b/chrome/moz.build
index b373e4ea48dd..d41e0ba50116 100644
--- a/chrome/moz.build
+++ b/chrome/moz.build
@@ -41,7 +41,7 @@ LOCAL_INCLUDES += [
 ]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 with Files("**"):
     BUG_COMPONENT = ("Toolkit", "Startup and Profile System")
diff --git a/dom/base/moz.build b/dom/base/moz.build
index 7b4603d2de87..48877fe13590 100644
--- a/dom/base/moz.build
+++ b/dom/base/moz.build
@@ -573,8 +573,8 @@ include("/ipc/chromium/chromium-config.mozbuild")
 
 FINAL_LIBRARY = "xul"
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+if CONFIG["MOZ_X11"]:
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 GeneratedFile(
     "UseCounterList.h",
diff --git a/dom/canvas/moz.build b/dom/canvas/moz.build
index 59ea18deaf86..5dde7e71aba9 100644
--- a/dom/canvas/moz.build
+++ b/dom/canvas/moz.build
@@ -202,8 +202,7 @@ LOCAL_INCLUDES += [
     "/media/libyuv/libyuv/include",
 ]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 LOCAL_INCLUDES += CONFIG["SKIA_INCLUDES"]
 
diff --git a/dom/file/ipc/moz.build b/dom/file/ipc/moz.build
index 4581c71cfa47..f4c7cc28c546 100644
--- a/dom/file/ipc/moz.build
+++ b/dom/file/ipc/moz.build
@@ -65,8 +65,7 @@ include("/tools/fuzzing/libfuzzer-config.mozbuild")
 
 FINAL_LIBRARY = "xul"
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 BROWSER_CHROME_MANIFESTS += ["tests/browser.ini"]
 MOCHITEST_MANIFESTS += ["tests/mochitest.ini"]
diff --git a/dom/ipc/moz.build b/dom/ipc/moz.build
index 355738f74acd..a93211617256 100644
--- a/dom/ipc/moz.build
+++ b/dom/ipc/moz.build
@@ -247,8 +247,7 @@ MOCHITEST_CHROME_MANIFESTS += ["tests/chrome.ini"]
 MOCHITEST_MANIFESTS += ["tests/mochitest.ini"]
 XPCSHELL_TESTS_MANIFESTS += ["tests/xpcshell.ini"]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 if CONFIG["FUZZING"] and CONFIG["FUZZING_INTERFACES"]:
     TEST_DIRS += ["fuzztest"]
diff --git a/dom/media/platforms/ffmpeg/ffmpeg58/moz.build b/dom/media/platforms/ffmpeg/ffmpeg58/moz.build
index febf20746d61..50d79b6ed457 100644
--- a/dom/media/platforms/ffmpeg/ffmpeg58/moz.build
+++ b/dom/media/platforms/ffmpeg/ffmpeg58/moz.build
@@ -26,7 +26,7 @@ if CONFIG['CC_TYPE'] == 'gcc':
     '-Wno-attributes',
   ]
 if CONFIG['MOZ_WAYLAND']:
-  CXXFLAGS += CONFIG['MOZ_GTK3_CFLAGS']
+  CXXFLAGS += CONFIG['TK_CFLAGS']
   DEFINES['MOZ_WAYLAND_USE_VAAPI'] = 1
   UNIFIED_SOURCES += [
     '../FFmpegVideoFramePool.cpp',
diff --git a/dom/media/platforms/ffmpeg/ffvpx/moz.build b/dom/media/platforms/ffmpeg/ffvpx/moz.build
index 854f23d94915..728f766de556 100644
--- a/dom/media/platforms/ffmpeg/ffvpx/moz.build
+++ b/dom/media/platforms/ffmpeg/ffvpx/moz.build
@@ -37,7 +37,7 @@ DEFINES["FFVPX_VERSION"] = 46465650
 DEFINES["USING_MOZFFVPX"] = True
 
 if CONFIG["MOZ_WAYLAND"]:
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
     DEFINES["MOZ_WAYLAND_USE_VAAPI"] = 1
 
 FINAL_LIBRARY = "xul"
diff --git a/dom/plugins/base/moz.build b/dom/plugins/base/moz.build
index 1e1348333644..c4d1df7ebfee 100644
--- a/dom/plugins/base/moz.build
+++ b/dom/plugins/base/moz.build
@@ -41,5 +41,4 @@ include("/ipc/chromium/chromium-config.mozbuild")
 
 FINAL_LIBRARY = "xul"
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
diff --git a/gfx/gl/moz.build b/gfx/gl/moz.build
index 03434957ccb5..368490d06ba3 100644
--- a/gfx/gl/moz.build
+++ b/gfx/gl/moz.build
@@ -150,9 +150,8 @@ FINAL_LIBRARY = "xul"
 if CONFIG["MOZ_D3DCOMPILER_VISTA_DLL"]:
     DEFINES["MOZ_D3DCOMPILER_VISTA_DLL"] = CONFIG["MOZ_D3DCOMPILER_VISTA_DLL"]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
+CFLAGS += CONFIG["TK_CFLAGS"]
 
 CXXFLAGS += ["-Werror=switch"]
 
diff --git a/gfx/ipc/moz.build b/gfx/ipc/moz.build
index f3917c333eec..3714505b118a 100644
--- a/gfx/ipc/moz.build
+++ b/gfx/ipc/moz.build
@@ -79,9 +79,7 @@ include("/ipc/chromium/chromium-config.mozbuild")
 
 FINAL_LIBRARY = "xul"
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 CXXFLAGS += ["-Werror=switch"]
 
 LOCAL_INCLUDES += CONFIG["SKIA_INCLUDES"]
diff --git a/gfx/layers/moz.build b/gfx/layers/moz.build
index e8b1f6c56f4b..ac141ad10e63 100755
--- a/gfx/layers/moz.build
+++ b/gfx/layers/moz.build
@@ -495,9 +495,7 @@ if CONFIG["ENABLE_TESTS"]:
 MOCHITEST_MANIFESTS += ["apz/test/mochitest/mochitest.ini"]
 BROWSER_CHROME_MANIFESTS += ["apz/test/mochitest/browser.ini"]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 CXXFLAGS += ["-Werror=switch"]
 
 LOCAL_INCLUDES += CONFIG["SKIA_INCLUDES"]
diff --git a/gfx/src/moz.build b/gfx/src/moz.build
index 2790a512cd30..6e5d1e2e7895 100644
--- a/gfx/src/moz.build
+++ b/gfx/src/moz.build
@@ -91,6 +91,7 @@ LOCAL_INCLUDES += [
 
 FINAL_LIBRARY = "xul"
 
+CXXFLAGS += CONFIG["TK_CFLAGS"]
+
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
     CXXFLAGS += CONFIG["MOZ_PANGO_CFLAGS"]
diff --git a/gfx/thebes/moz.build b/gfx/thebes/moz.build
index 0b6719692686..baa6f090a9a3 100644
--- a/gfx/thebes/moz.build
+++ b/gfx/thebes/moz.build
@@ -272,12 +272,13 @@ if CONFIG["MOZ_WIDGET_TOOLKIT"] == "windows":
         if CONFIG[var]:
             DEFINES[var] = True
 
+CXXFLAGS += CONFIG["TK_CFLAGS"]
+CFLAGS += CONFIG["TK_CFLAGS"]
+
 if CONFIG["MOZ_WIDGET_TOOLKIT"] in ("android"):
     CXXFLAGS += CONFIG["CAIRO_FT_CFLAGS"]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
     CXXFLAGS += CONFIG["MOZ_PANGO_CFLAGS"]
 
 if CONFIG["MOZ_WAYLAND"]:
diff --git a/gfx/vr/moz.build b/gfx/vr/moz.build
index ec56fc56341d..11e02c85a1af 100644
--- a/gfx/vr/moz.build
+++ b/gfx/vr/moz.build
@@ -91,9 +91,8 @@ if CONFIG["OS_ARCH"] == "WINNT":
     LOCAL_INCLUDES += ["/layout/generic", "/widget", "/widget/windows"]
     SOURCES += ["FxROutputHandler.cpp", "FxRWindowManager.cpp"]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
+CFLAGS += CONFIG["TK_CFLAGS"]
 
 include("/ipc/chromium/chromium-config.mozbuild")
 
diff --git a/gfx/webrender_bindings/moz.build b/gfx/webrender_bindings/moz.build
index 0f168f303615..bbcf10875a93 100644
--- a/gfx/webrender_bindings/moz.build
+++ b/gfx/webrender_bindings/moz.build
@@ -124,7 +124,5 @@ FINAL_LIBRARY = "xul"
 LOCAL_INCLUDES += [
     "/gfx/cairo/cairo/src",
 ]
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 CXXFLAGS += ["-Werror=switch"]
diff --git a/image/decoders/icon/gtk/moz.build b/image/decoders/icon/gtk/moz.build
index 3eac86b6baa6..1acddeec3412 100644
--- a/image/decoders/icon/gtk/moz.build
+++ b/image/decoders/icon/gtk/moz.build
@@ -14,7 +14,6 @@ EXPORTS += [
 
 FINAL_LIBRARY = "xul"
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 include("/ipc/chromium/chromium-config.mozbuild")
diff --git a/ipc/chromium/moz.build b/ipc/chromium/moz.build
index 0a9ab349d40a..49aaf14c51a1 100644
--- a/ipc/chromium/moz.build
+++ b/ipc/chromium/moz.build
@@ -123,8 +123,7 @@ if os_solaris:
         "src/base/time_posix.cc",
     ]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 TEST_DIRS += [
     "gtest",
diff --git a/ipc/ipdl/moz.build b/ipc/ipdl/moz.build
index 320c2e2f85cb..b5f01c526782 100644
--- a/ipc/ipdl/moz.build
+++ b/ipc/ipdl/moz.build
@@ -15,8 +15,7 @@ FINAL_LIBRARY = "xul"
 
 # We #include some things in the dom/plugins/ directory that rely on
 # toolkit libraries.
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 # Add libFuzzer configuration directives
 include("/tools/fuzzing/libfuzzer-config.mozbuild")
diff --git a/js/xpconnect/shell/moz.build b/js/xpconnect/shell/moz.build
index 5048fa7608ae..55f9356af95e 100644
--- a/js/xpconnect/shell/moz.build
+++ b/js/xpconnect/shell/moz.build
@@ -68,7 +68,6 @@ if CONFIG["OS_TARGET"] == "Darwin":
         "-framework Foundation",
     ]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    OS_LIBS += CONFIG["MOZ_GTK3_LIBS"]
+CFLAGS += CONFIG["TK_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
+OS_LIBS += CONFIG["TK_LIBS"]
diff --git a/layout/generic/moz.build b/layout/generic/moz.build
index 341d399a2f15..d4adfa37c270 100644
--- a/layout/generic/moz.build
+++ b/layout/generic/moz.build
@@ -266,4 +266,4 @@ MOCHITEST_MANIFESTS += ["test/mochitest.ini"]
 MOCHITEST_CHROME_MANIFESTS += ["test/chrome.ini"]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
diff --git a/layout/xul/moz.build b/layout/xul/moz.build
index be536100becb..4b71eb94bc0e 100644
--- a/layout/xul/moz.build
+++ b/layout/xul/moz.build
@@ -53,9 +53,8 @@ UNIFIED_SOURCES += [
 
 DIRS += ["tree"]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CFLAGS += CONFIG["TK_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 include("/ipc/chromium/chromium-config.mozbuild")
 
diff --git a/netwerk/protocol/gio/moz.build b/netwerk/protocol/gio/moz.build
index 4078e5605c81..7e28502558dd 100644
--- a/netwerk/protocol/gio/moz.build
+++ b/netwerk/protocol/gio/moz.build
@@ -35,8 +35,7 @@ LOCAL_INCLUDES += [
 
 FINAL_LIBRARY = "xul"
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 with Files("**"):
     BUG_COMPONENT = ("Core", "Widget: Gtk")
diff --git a/old-configure.in b/old-configure.in
index df08738c3640..fdcef71846ef 100644
--- a/old-configure.in
+++ b/old-configure.in
@@ -45,6 +45,13 @@ _SUBDIR_CONFIG_ARGS="$ac_configure_args"
 
 dnl Set the minimum version of toolkit libs used by mozilla
 dnl ========================================================
+GLIB_VERSION=2.42
+GLIB_VERSION_MIN_REQUIRED=GLIB_VERSION_2_42
+GLIB_VERSION_MAX_ALLOWED=GLIB_VERSION_2_42
+CAIRO_VERSION=1.10
+GTK3_VERSION=3.14.0
+GDK_VERSION_MIN_REQUIRED=GDK_VERSION_3_14
+GDK_VERSION_MAX_ALLOWED=GDK_VERSION_3_14
 W32API_VERSION=3.14
 
 dnl Set various checks
@@ -1241,6 +1248,35 @@ dnl =
 dnl ========================================================
 MOZ_ARG_HEADER(Toolkit Options)
 
+dnl ========================================================
+dnl = Enable the toolkit as needed                         =
+dnl ========================================================
+
+dnl there are a lot of tests on MOZ_ENABLE_GTK below, that are more convenient
+dnl to keep that way than testing against MOZ_WIDGET_TOOLKIT
+case "$MOZ_WIDGET_TOOLKIT" in
+gtk*)
+    MOZ_ENABLE_GTK=1
+    ;;
+esac
+
+if test "$COMPILE_ENVIRONMENT"; then
+  if test "$MOZ_WIDGET_TOOLKIT" = gtk; then
+    PKG_CHECK_MODULES(MOZ_GTK3, gtk+-3.0 >= $GTK3_VERSION gtk+-unix-print-3.0 glib-2.0 gobject-2.0 gio-unix-2.0 $GDK_PACKAGES)
+    TK_CFLAGS=$MOZ_GTK3_CFLAGS
+    TK_LIBS=$MOZ_GTK3_LIBS
+    AC_DEFINE_UNQUOTED(GDK_VERSION_MIN_REQUIRED,$GDK_VERSION_MIN_REQUIRED)
+    AC_DEFINE_UNQUOTED(GDK_VERSION_MAX_ALLOWED,$GDK_VERSION_MAX_ALLOWED)
+  fi
+  if test "$MOZ_ENABLE_GTK"; then
+    AC_DEFINE_UNQUOTED(GLIB_VERSION_MIN_REQUIRED,$GLIB_VERSION_MIN_REQUIRED)
+    AC_DEFINE_UNQUOTED(GLIB_VERSION_MAX_ALLOWED,$GLIB_VERSION_MAX_ALLOWED)
+  fi
+fi # COMPILE_ENVIRONMENT
+
+AC_SUBST_LIST(TK_CFLAGS)
+AC_SUBST_LIST(TK_LIBS)
+
 dnl ========================================================
 dnl =
 dnl = Components & Features
@@ -1546,6 +1582,17 @@ dnl =
 dnl ========================================================
 MOZ_ARG_HEADER(Standalone module options (Not for building Mozilla))
 
+dnl Check for GLib.
+dnl ========================================================
+
+if test -z "$SKIP_PATH_CHECKS"; then
+if test -z "${GLIB_CFLAGS}" -o -z "${GLIB_LIBS}" ; then
+    if test "$MOZ_ENABLE_GTK" ; then
+        PKG_CHECK_MODULES(GLIB, glib-2.0 >= 1.3.7 gobject-2.0)
+    fi
+fi
+fi
+
 if test "$USE_FC_FREETYPE"; then
     if test "$COMPILE_ENVIRONMENT"; then
         dnl ========================================================
@@ -1869,6 +1916,10 @@ fi # COMPILE_ENVIRONMENT
 dnl Set various defines and substitutions
 dnl ========================================================
 
+if test "$ACCESSIBILITY" -a "$MOZ_ENABLE_GTK" ; then
+    AC_DEFINE(MOZ_ACCESSIBILITY_ATK)
+fi
+
 AC_SUBST(MOZ_DEV_EDITION)
 if test -n "$MOZ_DEV_EDITION"; then
     AC_DEFINE(MOZ_DEV_EDITION)
diff --git a/python/mozbuild/mozbuild/gn_processor.py b/python/mozbuild/mozbuild/gn_processor.py
index e358f770db0d..4f1d75cc7a07 100644
--- a/python/mozbuild/mozbuild/gn_processor.py
+++ b/python/mozbuild/mozbuild/gn_processor.py
@@ -471,7 +471,7 @@ def write_mozbuild(
             try:
                 if relsrcdir in write_mozbuild_variables["INCLUDE_TK_CFLAGS_DIRS"]:
                     mb.write('if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":\n')
-                    mb.write('    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]\n')
+                    mb.write('    CXXFLAGS += CONFIG["TK_CFLAGS"]\n')
             except KeyError:
                 pass
 
diff --git a/security/manager/ssl/tests/unit/tlsserver/cmd/moz.build b/security/manager/ssl/tests/unit/tlsserver/cmd/moz.build
index 68c891978e3a..5c6dbadc714b 100644
--- a/security/manager/ssl/tests/unit/tlsserver/cmd/moz.build
+++ b/security/manager/ssl/tests/unit/tlsserver/cmd/moz.build
@@ -27,5 +27,4 @@ USE_LIBS += [
     "tlsserver",
 ]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
diff --git a/security/sandbox/linux/broker/moz.build b/security/sandbox/linux/broker/moz.build
index f993bc99c5c4..8af381656a80 100644
--- a/security/sandbox/linux/broker/moz.build
+++ b/security/sandbox/linux/broker/moz.build
@@ -32,7 +32,7 @@ LOCAL_INCLUDES += [
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
     CXXFLAGS += CONFIG["GLIB_CFLAGS"]
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 FINAL_LIBRARY = "xul"
 
diff --git a/security/sandbox/linux/launch/moz.build b/security/sandbox/linux/launch/moz.build
index 50a017c18b86..765072e4cbc5 100644
--- a/security/sandbox/linux/launch/moz.build
+++ b/security/sandbox/linux/launch/moz.build
@@ -27,8 +27,7 @@ USE_LIBS += [
 ]
 
 # For the X11 socket domain inspection in SandboxLaunch:
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 FINAL_LIBRARY = "xul"
 
diff --git a/testing/tools/screenshot/moz.build b/testing/tools/screenshot/moz.build
index 829405856f1b..2a7bfce846df 100644
--- a/testing/tools/screenshot/moz.build
+++ b/testing/tools/screenshot/moz.build
@@ -9,8 +9,8 @@ if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk" and CONFIG["MOZ_X11"]:
     SOURCES += [
         "gdk-screenshot.cpp",
     ]
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    OS_LIBS += CONFIG["MOZ_GTK3_LIBS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
+    OS_LIBS += CONFIG["TK_LIBS"]
     if CONFIG["MOZ_ENABLE_DBUS"]:
         OS_LIBS += CONFIG["MOZ_DBUS_GLIB_LIBS"]
 
diff --git a/third_party/libwebrtc/api/transport/stun_types_gn/moz.build b/third_party/libwebrtc/api/transport/stun_types_gn/moz.build
index 4a740f276478..8ebe427eb316 100644
--- a/third_party/libwebrtc/api/transport/stun_types_gn/moz.build
+++ b/third_party/libwebrtc/api/transport/stun_types_gn/moz.build
@@ -6,7 +6,7 @@
   ### This moz.build was AUTOMATICALLY GENERATED from a GN config,  ###
   ### DO NOT edit it by hand.                                       ###
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 COMPILE_FLAGS["OS_INCLUDES"] = []
 AllowCompilerWarnings()
diff --git a/third_party/libwebrtc/modules/desktop_capture/desktop_capture_generic_gn/moz.build b/third_party/libwebrtc/modules/desktop_capture/desktop_capture_generic_gn/moz.build
index a5cf9234d122..428fd07964fe 100644
--- a/third_party/libwebrtc/modules/desktop_capture/desktop_capture_generic_gn/moz.build
+++ b/third_party/libwebrtc/modules/desktop_capture/desktop_capture_generic_gn/moz.build
@@ -6,7 +6,7 @@
   ### This moz.build was AUTOMATICALLY GENERATED from a GN config,  ###
   ### DO NOT edit it by hand.                                       ###
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 COMPILE_FLAGS["OS_INCLUDES"] = []
 AllowCompilerWarnings()
diff --git a/third_party/pipewire/libpipewire/moz.build b/third_party/pipewire/libpipewire/moz.build
index 3102b3cb69b7..275913e3dc03 100644
--- a/third_party/pipewire/libpipewire/moz.build
+++ b/third_party/pipewire/libpipewire/moz.build
@@ -8,8 +8,7 @@ SOURCES += [
     'mozpipewire.cpp',
 ]
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG['MOZ_GTK3_CFLAGS']
+CXXFLAGS += CONFIG['TK_CFLAGS']
 
 LOCAL_INCLUDES += ['/third_party/pipewire']
 
diff --git a/toolkit/components/downloads/moz.build b/toolkit/components/downloads/moz.build
index d4172e2d73ad..19ae8dcb56f4 100644
--- a/toolkit/components/downloads/moz.build
+++ b/toolkit/components/downloads/moz.build
@@ -17,8 +17,7 @@ XPIDL_SOURCES += [
 
 XPIDL_MODULE = "downloads"
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 SOURCES += [
     "DownloadPlatform.cpp",
diff --git a/toolkit/components/protobuf/moz.build b/toolkit/components/protobuf/moz.build
index a94e48fa2767..871a757adfe4 100644
--- a/toolkit/components/protobuf/moz.build
+++ b/toolkit/components/protobuf/moz.build
@@ -142,5 +142,4 @@ if CONFIG['MOZ_USE_PTHREADS']:
 # Needed for the gzip streams.
 DEFINES['HAVE_ZLIB'] = True
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG['MOZ_GTK3_CFLAGS']
+CXXFLAGS += CONFIG['TK_CFLAGS']
diff --git a/toolkit/components/remote/moz.build b/toolkit/components/remote/moz.build
index d3bab6cf9a91..c1853a9f4d98 100644
--- a/toolkit/components/remote/moz.build
+++ b/toolkit/components/remote/moz.build
@@ -32,7 +32,7 @@ if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
             "nsXRemoteClient.cpp",
             "nsXRemoteServer.cpp",
         ]
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "windows":
     SOURCES += [
diff --git a/toolkit/crashreporter/client/moz.build b/toolkit/crashreporter/client/moz.build
index 48c4499914d7..1fb94cca8a32 100644
--- a/toolkit/crashreporter/client/moz.build
+++ b/toolkit/crashreporter/client/moz.build
@@ -82,9 +82,9 @@ if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
     USE_LIBS += [
         "breakpad_linux_common_s",
     ]
-    OS_LIBS += CONFIG["MOZ_GTK3_LIBS"]
+    OS_LIBS += CONFIG["TK_LIBS"]
     OS_LIBS += CONFIG["MOZ_GTHREAD_LIBS"]
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
     CXXFLAGS += CONFIG["MOZ_GTHREAD_CFLAGS"]
 
 if CONFIG["OS_ARCH"] == "Linux" or CONFIG["OS_ARCH"] == "SunOS":
diff --git a/toolkit/library/moz.build b/toolkit/library/moz.build
index 0b21d73c8c6d..5d70297a1313 100644
--- a/toolkit/library/moz.build
+++ b/toolkit/library/moz.build
@@ -319,7 +319,7 @@ if CONFIG["MOZ_ENABLE_DBUS"]:
     OS_LIBS += CONFIG["MOZ_DBUS_GLIB_LIBS"]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    OS_LIBS += [l for l in CONFIG["MOZ_GTK3_LIBS"] if l not in ("-lgtk-3", "-lgdk-3")]
+    OS_LIBS += [l for l in CONFIG["TK_LIBS"] if l not in ("-lgtk-3", "-lgdk-3")]
     OS_LIBS += CONFIG["MOZ_X11_LIBS"]
     OS_LIBS += CONFIG["MOZ_PANGO_LIBS"]
 
diff --git a/toolkit/moz.configure b/toolkit/moz.configure
index 429dbc73959b..a6f1c69f6383 100644
--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -1418,6 +1418,7 @@ def accessibility(value, check_for_midl, midl, c_compiler):
 
 set_config("ACCESSIBILITY", accessibility)
 set_define("ACCESSIBILITY", accessibility)
+add_old_configure_assignment("ACCESSIBILITY", accessibility)
 
 
 # Addon signing
@@ -2679,24 +2680,6 @@ with only_when(compile_environment):
         )
 
 
-# Gtk+
-# ==============================================================
-with only_when(toolkit_gtk):
-    pkg_check_modules(
-        "MOZ_GTK3",
-        "gtk+-3.0 >= 3.14.0 gtk+-unix-print-3.0 glib-2.0 gobject-2.0 gio-unix-2.0",
-    )
-
-    set_define("GDK_VERSION_MIN_REQUIRED", "GDK_VERSION_3_14")
-    set_define("GDK_VERSION_MAX_ALLOWED", "GDK_VERSION_3_14")
-
-    pkg_check_modules("GLIB", "glib-2.0 >= 2.42 gobject-2.0")
-
-    set_define("GLIB_VERSION_MIN_REQUIRED", "GLIB_VERSION_2_42")
-    set_define("GLIB_VERSION_MAX_ALLOWED", "GLIB_VERSION_2_42")
-
-    set_define("MOZ_ACCESSIBILITY_ATK", True, when=accessibility)
-
 # DBus
 # ==============================================================
 with only_when(toolkit_gtk):
diff --git a/toolkit/mozapps/update/updater/updater-common.build b/toolkit/mozapps/update/updater/updater-common.build
index 95d1ab892485..13926ea82046 100644
--- a/toolkit/mozapps/update/updater/updater-common.build
+++ b/toolkit/mozapps/update/updater/updater-common.build
@@ -109,8 +109,8 @@ elif CONFIG["OS_ARCH"] == "WINNT":
     WIN32_EXE_LDFLAGS += ["-municode"]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-    OS_LIBS += CONFIG["MOZ_GTK3_LIBS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
+    OS_LIBS += CONFIG["TK_LIBS"]
 
 if CONFIG["CC_TYPE"] == "gcc":
     CXXFLAGS += ["-Wno-format-truncation"]
diff --git a/toolkit/system/gnome/moz.build b/toolkit/system/gnome/moz.build
index a1b4aa29f250..0fc94ed9e39a 100644
--- a/toolkit/system/gnome/moz.build
+++ b/toolkit/system/gnome/moz.build
@@ -29,4 +29,4 @@ LOCAL_INCLUDES += [
 
 CXXFLAGS += CONFIG["GLIB_CFLAGS"]
 CXXFLAGS += CONFIG["MOZ_DBUS_GLIB_CFLAGS"]
-CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
diff --git a/toolkit/xre/moz.build b/toolkit/xre/moz.build
index b1e2b58621d6..e39d75d60330 100644
--- a/toolkit/xre/moz.build
+++ b/toolkit/xre/moz.build
@@ -268,11 +268,11 @@ if CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
         "/xpcom/base",
     ]
 
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 CXXFLAGS += CONFIG["MOZ_DBUS_CFLAGS"]
 CXXFLAGS += CONFIG["MOZ_DBUS_GLIB_CFLAGS"]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
     CXXFLAGS += CONFIG["MOZ_PANGO_CFLAGS"]
 
 DEFINES["TOPOBJDIR"] = TOPOBJDIR
diff --git a/uriloader/exthandler/moz.build b/uriloader/exthandler/moz.build
index 55ca63875429..8bac7bcfa376 100644
--- a/uriloader/exthandler/moz.build
+++ b/uriloader/exthandler/moz.build
@@ -134,10 +134,11 @@ LOCAL_INCLUDES += [
 ]
 
 if CONFIG["MOZ_ENABLE_DBUS"]:
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
     CXXFLAGS += CONFIG["MOZ_DBUS_CFLAGS"]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
     CXXFLAGS += CONFIG["MOZ_DBUS_GLIB_CFLAGS"]
 
 REQUIRES_UNIFIED_BUILD = True
diff --git a/widget/gtk/moz.build b/widget/gtk/moz.build
index 3e7a13c95a57..06b29cb23c8f 100644
--- a/widget/gtk/moz.build
+++ b/widget/gtk/moz.build
@@ -153,8 +153,8 @@ DEFINES["CAIRO_GFX"] = True
 
 DEFINES["MOZ_APP_NAME"] = '"%s"' % CONFIG["MOZ_APP_NAME"]
 
-CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CFLAGS += CONFIG["TK_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 if CONFIG["MOZ_WAYLAND"]:
     CFLAGS += CONFIG["MOZ_WAYLAND_CFLAGS"]
diff --git a/widget/gtk/mozwayland/moz.build b/widget/gtk/mozwayland/moz.build
index 0df3f0f6857a..94eca8a78523 100644
--- a/widget/gtk/mozwayland/moz.build
+++ b/widget/gtk/mozwayland/moz.build
@@ -13,4 +13,4 @@ EXPORTS.mozilla.widget += [
 
 SharedLibrary("mozwayland")
 
-CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CFLAGS += CONFIG["TK_CFLAGS"]
diff --git a/widget/gtk/wayland/moz.build b/widget/gtk/wayland/moz.build
index 2bd15b3844e7..34fea9144754 100644
--- a/widget/gtk/wayland/moz.build
+++ b/widget/gtk/wayland/moz.build
@@ -37,5 +37,5 @@ include("/ipc/chromium/chromium-config.mozbuild")
 
 FINAL_LIBRARY = "xul"
 
-CFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
-CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CFLAGS += CONFIG["TK_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
diff --git a/widget/moz.build b/widget/moz.build
index 6b1998c0c097..2f0d254b7d1a 100644
--- a/widget/moz.build
+++ b/widget/moz.build
@@ -347,8 +347,7 @@ FINAL_LIBRARY = "xul"
 if CONFIG["MOZ_ENABLE_D3D10_LAYER"]:
     DEFINES["MOZ_ENABLE_D3D10_LAYER"] = True
 
-if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+CXXFLAGS += CONFIG["TK_CFLAGS"]
 if CONFIG["MOZ_WAYLAND"]:
     CXXFLAGS += CONFIG["MOZ_WAYLAND_CFLAGS"]
 
diff --git a/xpcom/base/moz.build b/xpcom/base/moz.build
index 90df35b63585..8780ca11853e 100644
--- a/xpcom/base/moz.build
+++ b/xpcom/base/moz.build
@@ -263,7 +263,7 @@ LOCAL_INCLUDES += [
 ]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
 
 if CONFIG["MOZ_BACKGROUNDTASKS"]:
     DEFINES["MOZ_BACKGROUNDTASKS"] = True
diff --git a/xpcom/components/moz.build b/xpcom/components/moz.build
index 6cf78aa9bec5..655e2a607a4a 100644
--- a/xpcom/components/moz.build
+++ b/xpcom/components/moz.build
@@ -74,7 +74,7 @@ LOCAL_INCLUDES += [
 ]
 
 if CONFIG["MOZ_WIDGET_TOOLKIT"] == "gtk":
-    CXXFLAGS += CONFIG["MOZ_GTK3_CFLAGS"]
+    CXXFLAGS += CONFIG["TK_CFLAGS"]
     if CONFIG["MOZ_ENABLE_DBUS"]:
         CXXFLAGS += CONFIG["MOZ_DBUS_GLIB_CFLAGS"]