diff --git a/compat-usrmerge.changes b/compat-usrmerge.changes
index a873f68..94eb82c 100644
--- a/compat-usrmerge.changes
+++ b/compat-usrmerge.changes
@@ -1,3 +1,8 @@
+-------------------------------------------------------------------
+Tue Jun  8 12:03:52 UTC 2021 - Ludwig Nussel <lnussel@suse.de>
+
+- early exit in case of overlayfs (boo#1187027)
+
 -------------------------------------------------------------------
 Tue Jun  8 07:37:33 UTC 2021 - Fabian Vogt <fvogt@suse.com>
 
diff --git a/convertfs b/convertfs
index 01cc310..e82a95d 100644
--- a/convertfs
+++ b/convertfs
@@ -3,6 +3,19 @@
 
 ROOT=
 
+is_usrmerged() {
+    local r=1
+    for dir in bin sbin lib lib64; do
+	[ -d "$ROOT/$dir" ] || continue
+	[ -L "$ROOT/$dir" ] || return 1
+	r=0
+    done
+    return "$r"
+}
+
+# check if there's anything to do
+is_usrmerged && exit 0
+
 # the package is installed with AutoReq off, so no guarantee that
 # coreutils actually works
 if ! { cp --help && find --help; } > /dev/null; then
@@ -12,7 +25,7 @@ fi
 
 # clean up after ourselves no matter how we die.
 cleanup() {
-    echo "Something failed, cleaning up"
+    echo "UsrMerge conversion failed, cleaning up"
     for dir in bin sbin lib lib64; do
 	rm -rf -- "$ROOT/usr/${dir}.usrmerge"
     done
@@ -26,10 +39,16 @@ trap 'exit 1;' SIGINT
 
 set -e
 
-usrismountpoint=
+if [ "$(stat -f -c %T "${ROOT:-/}")" = "overlayfs" ]; then
+	echo "UsrMerge conversion does not work on overlayfs"
+	exit 1
+fi
+
+CP_HARDLINK="-l"
 while read dev mp other; do
-    [ "$mp" = "/usr" ] && usrismountpoint=1
+    [ "$mp" = "$ROOT/usr" ] && CP_HARDLINK=""
     for dir in bin sbin lib lib64; do
+	[ -d "$ROOT/$dir" ] || continue
 	if [ "${mp#$ROOT/$dir}" != "$mp" ] || [ "${mp#$ROOT/usr/$dir}" != "$mp" ]; then
 	    echo "Please unmount $mp before the conversion"
 	    exit 1
@@ -37,8 +56,6 @@ while read dev mp other; do
     done
 done < /proc/mounts
 
-[ -n "$usrismountpoint" ] || CP_HARDLINK="-l"
-
 # merge / and /usr in new dir in /usr
 for dir in bin sbin lib lib64; do
     rm -rf -- "$ROOT/usr/${dir}.usrmerge"