diff --git a/signer/config.json b/signer/config.json
index 60de5e0c7..5f7feb9ef 100644
--- a/signer/config.json
+++ b/signer/config.json
@@ -1,7 +1,7 @@
 {
 	"whitelist_urls": [
                 "https?://localhost(:\\d+)?(/.*)?",
-                "https?://localhost.mytrezor.com(:\\d+)?(/.*)?",
+                "https?://localhost\\.mytrezor\\.com(:\\d+)?(/.*)?",
                 "https://mytrezor\\.com(/.*)?",
                 "https://[\\w\\.-]+\\.mytrezor\\.com(/.*)?",
                 "https://greenaddress\\.it(/.*)?",