diff --git a/share/functions/contains.fish b/share/functions/contains.fish
index 64f8c45..72edc9e 100644
--- a/share/functions/contains.fish
+++ b/share/functions/contains.fish
@@ -32,6 +32,9 @@ function contains -d (N_ "Test if a key is contained in a set of values")
 	set -- key $argv[1]
 	set -e argv[1]	
 
+	# Don't use any grep options!
+	set -l GREP_OPTIONS
+
 	#
 	# Loop through values
 	#