diff --git a/fire/completion.py b/fire/completion.py
index 9659ec6a..4393880d 100644
--- a/fire/completion.py
+++ b/fire/completion.py
@@ -104,7 +104,7 @@ def _BashScript(name, commands, default_options=None):
 option_already_entered()
 {{
   local opt
-  for opt in ${{COMP_WORDS[@]:0:COMP_CWORD}}
+  for opt in ${{COMP_WORDS[@]:0:$COMP_CWORD}}
   do
     if [ $1 == $opt ]; then
       return 0