diff --git a/webpacker.gemspec b/webpacker.gemspec
index eeb656e60..c3310bb47 100644
--- a/webpacker.gemspec
+++ b/webpacker.gemspec
@@ -17,8 +17,8 @@ Gem::Specification.new do |s|
 
   s.required_ruby_version = ">= 2.3.0"
 
-  s.add_dependency "activesupport", "= 3.2.22"
-  s.add_dependency "railties",      "= 3.2.22"
+  s.add_dependency "activesupport", ">= 4.0.0"
+  s.add_dependency "railties",      ">= 4.0.0"
   s.add_dependency "rack-proxy",    ">= 0.6.1"
   s.add_dependency "semantic_range", ">= 2.3.0"