diff --git a/manifests/guess.pp b/manifests/guess.pp
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+# Copyright © 2017   Thomas Bellman, Linköping, Sweden
+# Licensed under the GNU LGPL v3+; see the README file for more information.
+
+
+/*
+ * Try to guess what bootloader is in use, based on the OS.
+ * Sets the $bootloader variable to the guess.
+ * The heuristics used are not very good...
+ * This is intended as an internal helper class, not for end users.
+ */
+class bootloader::guess
+{
+    if ($::operatingsystem == 'Fedora' and
+	versioncmp($::operatingsystemrelease, '18') >= 0)
+    {
+	$bootloader = 'grub2'
+    }
+    elsif ($::operatingsystem == 'Fedora' and
+	   versioncmp($::operatingsystemrelease, '15') < 0)
+    {
+	$bootloader = 'grub0'
+    }
+    elsif ($::osfamily == 'RedHat'  and
+	   versioncmp($::operatingsystemrelease, '7') >= 0)
+    {
+	$bootloader = 'grub2'
+    }
+    elsif ($::osfamily == 'RedHat'  and
+	   versioncmp($::operatingsystemrelease, '7') < 0)
+    {
+	$bootloader = 'grub0'
+    }
+    else
+    {
+	fail("Cannot guess what bootloader is in use.")
+    }
+}