diff --git a/files/bashrc.d/70-util-grep.sh b/files/bashrc.d/70-util-grep.sh
index 60e0992..6801543 100644
--- a/files/bashrc.d/70-util-grep.sh
+++ b/files/bashrc.d/70-util-grep.sh
@@ -5,5 +5,5 @@
 #export GREP_COLORS
 
 # disable deprecated variable
-export GREP_OPTIONS=
+unset GREP_OPTIONS