diff --git a/src/main.cr b/src/main.cr
index ba0ca32..28c7a74 100644
--- a/src/main.cr
+++ b/src/main.cr
@@ -234,7 +234,7 @@ class RootFS::RootFS
 
 	def unmount(directory = nil)
 		if directory
-			execute "umount '#{@directory}/#{directory}'"
+			execute "mountpoint -q '#{@directory}/#{directory}' || exit 0 && umount '#{@directory}/#{directory}'"
 			return
 		end