diff --git a/DistUpgrade/DistUpgradeViewGtk3.py b/DistUpgrade/DistUpgradeViewGtk3.py
index 56a807b..2071a3e 100644
--- a/DistUpgrade/DistUpgradeViewGtk3.py
+++ b/DistUpgrade/DistUpgradeViewGtk3.py
@@ -201,11 +201,11 @@ class GtkInstallProgressAdapter(InstallProgress):
         self.expander.set_sensitive(True)
         self.term.show()
         self.term.connect("contents-changed", self._on_term_content_changed)
-        # if no libgtk2-perl is installed show the terminal
+        # if no libgtk3-perl is installed show the terminal
         frontend= os.environ.get("DEBIAN_FRONTEND") or "gnome"
         if frontend == "gnome" and self._cache:
-            if (not "libgtk2-perl" in self._cache or
-                not self._cache["libgtk2-perl"].is_installed):
+            if (not "libgtk3-perl" in self._cache or
+                not self._cache["libgtk3-perl"].is_installed):
                 frontend = "dialog"
                 self.expander.set_expanded(True)
         self.env = ["VTE_PTY_KEEP_FD=%s"% self.writefd,
diff --git a/debian/changelog b/debian/changelog
index cac0bd6..46ac648 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+ubuntu-release-upgrader (1:20.04.18) UNRELEASED; urgency=medium
+
+  * Use libgtk3-perl, not libgtk2-perl, to decide whether to use the gnome
+    debconf frontend; debconf migrated to GTK+3 in version 1.5.66, before
+    bionic was released.  LP: #1871530.
+
+ -- Steve Langasek <steve.langasek@ubuntu.com>  Tue, 07 Apr 2020 21:05:11 -0700
+
 ubuntu-release-upgrader (1:20.04.17) focal; urgency=medium
 
   * DistUpgrade/DistUpgradeFetcher.py,