diff --git a/Gemfile b/Gemfile
index 70b12cc..27658c2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,3 +6,4 @@ rails_version = ENV.fetch("ACTIVE_SUPPORT_VERSION", "7.0")
 
 gem "activesupport", "~> #{rails_version}"
 gem "minitest", "~> 5.0"
+gem "ostruct"
diff --git a/clockwork.gemspec b/clockwork.gemspec
index db90de4..bd70a31 100644
--- a/clockwork.gemspec
+++ b/clockwork.gemspec
@@ -19,9 +19,6 @@ Gem::Specification.new do |s|
 
   s.add_dependency(%q<tzinfo>)
   s.add_dependency(%q<activesupport>)
-  s.add_dependency(%q<base64>)
-  s.add_dependency(%q<bigdecimal>)
-  s.add_dependency(%q<ostruct>)
 
   s.add_development_dependency "rake"
   s.add_development_dependency "daemons"