diff --git a/bin/openfile b/bin/openfile
index c0e2e9c..f6668dc 100755
--- a/bin/openfile
+++ b/bin/openfile
@@ -1,7 +1,7 @@
 #!/bin/sh
 
 # Helps open a file with xdg-open from mutt in a external program without weird side effects.
-[ $(uname) = "Darwin" ] && opener="open" || opener="setsid xdg-open"
+[ "$(uname)" = "Darwin" ] && opener="open" || opener="setsid xdg-open"
 mkdir -p "/tmp/$USER-mutt-tmp"
 file="/tmp/$USER-mutt-tmp/$(basename "$1")"
 rm -f "$file"