diff --git a/Formula/mage.rb b/Formula/mage.rb
index f6d7d9d2802..abdfe66caa5 100644
--- a/Formula/mage.rb
+++ b/Formula/mage.rb
@@ -23,7 +23,7 @@ class Mage < Formula
   def install
     ldflags = %W[
       -s -w
-      -X github.com/magefile/mage/mage.timestamp=#{time.rfc3339}
+      -X github.com/magefile/mage/mage.timestamp=#{time.iso8601}
       -X github.com/magefile/mage/mage.commitHash=#{Utils.git_short_head}
       -X github.com/magefile/mage/mage.gitTag=#{version}
     ]