diff --git a/webif/lib/utils b/webif/lib/utils
index e9b794b..7eb71e4 100644
--- a/webif/lib/utils
+++ b/webif/lib/utils
@@ -103,13 +103,13 @@ proc ::js::_unescape {str} {
 proc ::js::escape {str} {
 	return [subst -nobackslashes -novariables \
 		[regsub -all -- {[^A-Za-z0-9@*_+-./]+} $str \
-			{[::js::_escape "&"]}]]
+			{[::js::_escape {&}]}]]
 }
 
 proc ::js::unescape {str} {
 	return [subst -nobackslashes -novariables \
 		[regsub -all -- {%(u[[:xdigit:]]{2})?[[:xdigit:]]{2}} $str \
-			{[::js::_unescape "&"]}]]
+			{[::js::_unescape {&}]}]]
 }
 
 alias jsescape ::js::escape