diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index b92449d7647..aad38b94d76 100644
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -4341,6 +4341,7 @@ option followed by a colon `:' if the option accepts an argument."
 				t)
 	     (match-string 1))))))
 
+(put 'sh-assignment 'delete-selection t)
 
 (defun sh-maybe-here-document (arg)
   "Insert self.  Without prefix, following unquoted `<' inserts here document.