diff --git a/lib/grep.sh b/lib/grep.sh
index df48a9cc1..1679c6ce3 100644
--- a/lib/grep.sh
+++ b/lib/grep.sh
@@ -2,7 +2,7 @@
 
 # is x grep argument available?
 function _omb_grep_flag_available {
-  : | grep "$1" "" >/dev/null 2>&1
+  echo | grep "$1" "" >/dev/null 2>&1
 }
 
 _omb_grep_options=()