diff --git a/Gemfile.lock b/Gemfile.lock
index 310684934..575a90213 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -3,6 +3,7 @@ PATH
   specs:
     kamal (1.3.0)
       activesupport (>= 7.0)
+      base64 (~> 0.2)
       bcrypt_pbkdf (~> 1.0)
       concurrent-ruby (~> 1.2)
       dotenv (~> 2.8)
diff --git a/kamal.gemspec b/kamal.gemspec
index 8dcaa6eae..55f18ce9f 100644
--- a/kamal.gemspec
+++ b/kamal.gemspec
@@ -20,6 +20,7 @@ Gem::Specification.new do |spec|
   spec.add_dependency "ed25519", "~> 1.2"
   spec.add_dependency "bcrypt_pbkdf", "~> 1.0"
   spec.add_dependency "concurrent-ruby", "~> 1.2"
+  spec.add_dependency "base64", "~> 0.2"
 
   spec.add_development_dependency "debug"
   spec.add_development_dependency "mocha"
diff --git a/lib/kamal/commands/lock.rb b/lib/kamal/commands/lock.rb
index 823407143..607bd79d1 100644
--- a/lib/kamal/commands/lock.rb
+++ b/lib/kamal/commands/lock.rb
@@ -1,5 +1,6 @@
 require "active_support/duration"
 require "time"
+require "base64"
 
 class Kamal::Commands::Lock < Kamal::Commands::Base
   def acquire(message, version)