diff --git a/webif/lib/utils b/webif/lib/utils
index 7eb71e4..c7dbd84 100644
--- a/webif/lib/utils
+++ b/webif/lib/utils
@@ -102,7 +102,7 @@ proc ::js::_unescape {str} {
 
 proc ::js::escape {str} {
 	return [subst -nobackslashes -novariables \
-		[regsub -all -- {[^A-Za-z0-9@*_+-./]+} $str \
+		[regsub -all -- {[^A-Za-z0-9@*_+./-]+} $str \
 			{[::js::_escape {&}]}]]
 }