diff --git a/modules/misc/qt.nix b/modules/misc/qt.nix
index 90fdd140..f02bc186 100644
--- a/modules/misc/qt.nix
+++ b/modules/misc/qt.nix
@@ -209,7 +209,7 @@ in {
     systemd.user.sessionVariables = envVars // envVarsExtra;
 
     home.packages = (lib.optionals (cfg.platformTheme != null)
-      platformPackages.${cfg.platformTheme})
+      platformPackages.${cfg.platformTheme} or [ ])
       ++ (lib.optionals (cfg.style.package != null)
         (lib.toList cfg.style.package));
 
diff --git a/tests/modules/misc/qt/default.nix b/tests/modules/misc/qt/default.nix
index 44b6b96c..da27bf31 100644
--- a/tests/modules/misc/qt/default.nix
+++ b/tests/modules/misc/qt/default.nix
@@ -1,5 +1,6 @@
 {
   qt-basic = ./qt-basic.nix;
   qt-platform-theme-gtk = ./qt-platform-theme-gtk.nix;
+  qt-platform-theme-gtk3 = ./qt-platform-theme-gtk3.nix;
   qt-platform-theme-gnome = ./qt-platform-theme-gnome.nix;
 }
diff --git a/tests/modules/misc/qt/qt-platform-theme-gtk3.nix b/tests/modules/misc/qt/qt-platform-theme-gtk3.nix
new file mode 100644
index 00000000..2b3ade9d
--- /dev/null
+++ b/tests/modules/misc/qt/qt-platform-theme-gtk3.nix
@@ -0,0 +1,19 @@
+{ config, lib, pkgs, ... }:
+
+{
+  config = {
+    qt = {
+      enable = true;
+      platformTheme = "gtk3";
+    };
+
+    nmt.script = ''
+      assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
+        'QT_QPA_PLATFORMTHEME="gtk3"'
+      assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
+        'QT_PLUGIN_PATH'
+      assertFileRegex home-path/etc/profile.d/hm-session-vars.sh \
+        'QML2_IMPORT_PATH'
+    '';
+  };
+}