diff --git a/debian/changelog b/debian/changelog
index 89d5f48..15f530d 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+desktop-base (9.0.6) UNRELEASED; urgency=medium
+
+  * Improve detection of grub efi to choose default background ratio.
+
+ -- Aurélien COUDERC <zecoucou@free.fr>  Thu, 06 Jul 2017 17:09:44 +0200
+
 desktop-base (9.0.5) unstable; urgency=medium
 
   * Ensure postinst doesn’t fails on upgrade even when an incomplete theme pack
diff --git a/debian/postinst b/debian/postinst
index b240074..ebd2118 100644
--- a/debian/postinst
+++ b/debian/postinst
@@ -165,11 +165,16 @@ EOF
     # Set up an alternative for the GRUB background/colors config
     # Highest priority for active theme
     ## Favor widescreen / hi-res background for efi installations
-    num_grub_efi_installed=$(dpkg-query --list "grub-efi*" 2> /dev/null | grep "^i" | wc -l)
+    grub_installed_query="dpkg-query --list grub-efi*"
+    echo "Detecting installed grub-efi* packages..."
+    ${grub_installed_query} || true # log packages found if any
+    num_grub_efi_installed=$(${grub_installed_query} 2> /dev/null | grep "^i" | wc -l)
     if [ $num_grub_efi_installed -gt 0 ] ; then
+        echo "grub-efi found, using 16/9 as default grub background ratio"
         grub_first_ratio="16x9"
         grub_second_ratio="4x3"
     else
+        echo "grub-efi not found, using 4/3 as default grub background ratio"
         grub_first_ratio="4x3"
         grub_second_ratio="16x9"
     fi