diff --git a/debian/rules b/debian/rules
index 32b15279..075a35e9 100755
--- a/debian/rules
+++ b/debian/rules
@@ -7,7 +7,6 @@ export DH_VERBOSE=1
 
 override_dh_auto_configure:
 	dh_auto_configure -- \
-		-Dgtk3=true \
 		-Dinstall-plugin-metainfo=false \
 		-Dwith-lua=lua53
 
diff --git a/flatpak/net.zoite.Zoitechat.json b/flatpak/net.zoite.Zoitechat.json
index b7436edd..c0de3da1 100644
--- a/flatpak/net.zoite.Zoitechat.json
+++ b/flatpak/net.zoite.Zoitechat.json
@@ -56,14 +56,13 @@
       "name": "zoitechat",
       "buildsystem": "meson",
       "config-opts": [
-        "-Dgtk3=true",
         "-Ddbus-service-use-appid=true",
         "-Dwith-perl=false",
         "-Dwith-python=false",
         "-Dwith-lua=lua"
       ],
       "build-options": {
-        "cflags": "-Dgtk3=true -Wno-error=missing-include-dirs"
+        "cflags": "-Wno-error=missing-include-dirs"
       },
       "cleanup": [
         "/share/man"
diff --git a/meson_options.txt b/meson_options.txt
index fb087a5d..85fd73ee 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -2,9 +2,6 @@
 option('gtk-frontend', type: 'boolean',
   description: 'Main graphical interface'
 )
-option('gtk3', type: 'boolean', value: true, deprecated: true,
-  description: 'Deprecated: GTK frontend always builds against GTK 3'
-)
 option('text-frontend', type: 'boolean', value: false,
   description: 'Text interface (not generally useful)'
 )
diff --git a/packaging/solus/package.yml b/packaging/solus/package.yml
index 45ec53fe..ac791636 100644
--- a/packaging/solus/package.yml
+++ b/packaging/solus/package.yml
@@ -26,7 +26,6 @@ builddeps  :
 setup      : |
     %meson_configure \
         -Dgtk-frontend=true \
-        -Dgtk3=true \
         -Dinstall-appdata=true
 build      : |
     %ninja_build
diff --git a/plugins/sysinfo/osx/backend.m b/plugins/sysinfo/osx/backend.m
index 58001949..58b9485a 100644
--- a/plugins/sysinfo/osx/backend.m
+++ b/plugins/sysinfo/osx/backend.m
@@ -278,10 +278,6 @@ static const char *sysinfo_detect_toolkit(void)
 {
 #if defined(HAVE_GTK3)
 	return "GTK3";
-#elif defined(HAVE_GTK2)
-	return "GTK2";
-#elif defined(HAVE_GTK)
-	return "GTK";
 #else
 	return NULL;
 #endif
diff --git a/plugins/sysinfo/sysinfo-backend.h b/plugins/sysinfo/sysinfo-backend.h
index 3a8f2920..7d3776f1 100644
--- a/plugins/sysinfo/sysinfo-backend.h
+++ b/plugins/sysinfo/sysinfo-backend.h
@@ -32,7 +32,7 @@ char *sysinfo_backend_get_network(void);
 
 /*
  * Short description of the UI/toolkit + display backend.
- * Examples: "GTK3 / Wayland", "GTK2 / X11", "Windows / GTK3".
+ * Examples: "GTK3 / Wayland", "Windows / GTK3".
  */
 char *sysinfo_backend_get_ui(void);
 
diff --git a/plugins/sysinfo/unix/backend.c b/plugins/sysinfo/unix/backend.c
index b6069042..b53a201d 100644
--- a/plugins/sysinfo/unix/backend.c
+++ b/plugins/sysinfo/unix/backend.c
@@ -19,7 +19,7 @@
 
 #include <glib.h>
 
-#if defined(HAVE_GTK3) || defined(HAVE_GTK2) || defined(HAVE_GTK)
+#if defined(HAVE_GTK3)
 #include <gdk/gdk.h>
 #endif
 #include "parse.h"
@@ -177,10 +177,6 @@ static const char *sysinfo_detect_toolkit(void)
 {
 #if defined(HAVE_GTK3)
 	return "GTK3";
-#elif defined(HAVE_GTK2)
-	return "GTK2";
-#elif defined(HAVE_GTK)
-	return "GTK";
 #else
 	return NULL;
 #endif
@@ -194,7 +190,7 @@ static const char *sysinfo_detect_display_backend(void)
 	const gboolean session_wayland = session && g_ascii_strcasecmp(session, "wayland") == 0;
 
 	/* Best-effort: ask GDK what it actually opened, if available. */
-#if defined(HAVE_GTK3) || defined(HAVE_GTK2) || defined(HAVE_GTK)
+#if defined(HAVE_GTK3)
 	{
 		GdkDisplay *display = gdk_display_get_default();
 		if (display)
diff --git a/plugins/sysinfo/win32/backend.c b/plugins/sysinfo/win32/backend.c
index e6f9487f..e76402a7 100644
--- a/plugins/sysinfo/win32/backend.c
+++ b/plugins/sysinfo/win32/backend.c
@@ -108,10 +108,6 @@ static const char *sysinfo_detect_toolkit(void)
 {
 #if defined(HAVE_GTK3)
 	return "GTK3";
-#elif defined(HAVE_GTK2)
-	return "GTK2";
-#elif defined(HAVE_GTK)
-	return "GTK";
 #else
 	return NULL;
 #endif