diff --git a/Formula/zshdb.rb b/Formula/zshdb.rb
index e9cf707acae..bc3f464fdbc 100644
--- a/Formula/zshdb.rb
+++ b/Formula/zshdb.rb
@@ -25,7 +25,7 @@ class Zshdb < Formula
   end
 
   head do
-    url "https://github.com/rocky/zshdb.git"
+    url "https://github.com/rocky/zshdb.git", branch: "master"
     depends_on "autoconf" => :build
     depends_on "automake" => :build
   end