diff --git a/addon/lib/rmupdate.tcl b/addon/lib/rmupdate.tcl
index b095f0b..ad3666e 100644
--- a/addon/lib/rmupdate.tcl
+++ b/addon/lib/rmupdate.tcl
@@ -1044,7 +1044,9 @@ proc ::rmupdate::get_available_firmware_downloads {} {
 			if {[string first "https://" $href] == -1} {
 				set href "https://github.com${href}"
 			}
-			lappend download_urls "${href}.zip"
+			if {[lsearch -exact $download_urls "${href}.zip"] == -1} {
+				lappend download_urls "${href}.zip"
+			}
 		}
 	}
 	return $download_urls