diff --git a/rc/core/comment.kak b/rc/core/comment.kak
index ac2393cc..c33436cb 100644
--- a/rc/core/comment.kak
+++ b/rc/core/comment.kak
@@ -175,7 +175,7 @@ define-command comment-line -docstring '(un)comment selected lines using line co
 define-command align-selections-left -docstring 'extend selections to the left to align with the leftmost selected column' %{
     %sh{
         leftmost_column=$(echo "$kak_selections_desc" | tr ':' '\n' | cut -d',' -f1 | cut -d'.' -f2 | sort -n | head -n1)
-        aligned_selections=$(echo "$kak_selections_desc" | sed -r "s/\.[0-9]+,/.$leftmost_column,/g")
+        aligned_selections=$(echo "$kak_selections_desc" | sed -E "s/\.[0-9]+,/.$leftmost_column,/g")
         echo "select $aligned_selections"
     }
 }