diff --git a/pkgs/desktops/gnome/update.nix b/pkgs/desktops/gnome/update.nix
index f5db71174ad8..e945e005d48d 100644
--- a/pkgs/desktops/gnome/update.nix
+++ b/pkgs/desktops/gnome/update.nix
@@ -12,7 +12,13 @@ let
       minorAvailable = builtins.length versionComponents > 1 && builtins.match "[0-9]+" minorVersion != null;
       nextMinor = builtins.fromJSON minorVersion + 1;
       upperBound = "${lib.versions.major packageVersion}.${builtins.toString nextMinor}";
-    in lib.optionals (freeze && minorAvailable) [ upperBound ];
+    in
+    if builtins.isBool freeze then
+      lib.optionals (freeze && minorAvailable) [ upperBound ]
+    else if builtins.isString freeze then
+      [ freeze ]
+    else
+      throw "“freeze” argument needs to be either a boolean, or a version string.";
   updateScript = writeScript "gnome-update-script" ''
     #!${bash}/bin/bash
     set -o errexit