diff --git a/Gemfile.lock b/Gemfile.lock
index a25b383..651b743 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -2,7 +2,6 @@ PATH
   remote: .
   specs:
     buildkite-test_collector (2.4.0)
-      activesupport (>= 4.2)
 
 GEM
   remote: https://rubygems.org/
@@ -38,6 +37,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  activesupport (>= 4.2)
   buildkite-test_collector!
   rake (~> 13.0)
   rspec (~> 3.0)
diff --git a/buildkite-test_collector.gemspec b/buildkite-test_collector.gemspec
index c4d98d2..2c27b19 100644
--- a/buildkite-test_collector.gemspec
+++ b/buildkite-test_collector.gemspec
@@ -24,8 +24,7 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = Gem::Requirement.new(">= 2.3.0")
 
-  spec.add_dependency "activesupport", ">= 4.2"
-
+  spec.add_development_dependency "activesupport", ">= 4.2"
   spec.add_development_dependency "rspec-core", '~> 3.10'
   spec.add_development_dependency "rspec-expectations", '~> 3.10'
 end
diff --git a/lib/buildkite/test_collector.rb b/lib/buildkite/test_collector.rb
index 7abd033..751bc86 100644
--- a/lib/buildkite/test_collector.rb
+++ b/lib/buildkite/test_collector.rb
@@ -8,14 +8,11 @@ module TestCollector
 require "json"
 require "logger"
 require "net/http"
+require "openssl"
 require "time"
 require "timeout"
 require "tmpdir"
 
-require "active_support/core_ext/object/blank"
-require "active_support/core_ext/hash/indifferent_access"
-require "active_support/notifications"
-
 require_relative "test_collector/version"
 require_relative "test_collector/error"
 require_relative "test_collector/ci"
@@ -72,6 +69,10 @@ def self.enable_tracing!
       Buildkite::TestCollector::Network.configure
       Buildkite::TestCollector::Object.configure
 
+      return unless defined?(ActiveSupport)
+
+      require "active_support/notifications"
+
       ActiveSupport::Notifications.subscribe("sql.active_record") do |name, start, finish, id, payload|
         Buildkite::TestCollector::Uploader.tracer&.backfill(:sql, finish - start, **{ query: payload[:sql] })
       end
diff --git a/lib/buildkite/test_collector/minitest_plugin/trace.rb b/lib/buildkite/test_collector/minitest_plugin/trace.rb
index c0e53e3..e474bd6 100644
--- a/lib/buildkite/test_collector/minitest_plugin/trace.rb
+++ b/lib/buildkite/test_collector/minitest_plugin/trace.rb
@@ -38,7 +38,7 @@ def as_hash
         failure_reason: failure_reason,
         failure_expanded: failure_expanded,
         history: history,
-      ).with_indifferent_access.select { |_, value| !value.nil? }
+      ).select { |_, value| !value.nil? }
     end
 
     private
diff --git a/lib/buildkite/test_collector/rspec_plugin/reporter.rb b/lib/buildkite/test_collector/rspec_plugin/reporter.rb
index 5860bcf..609548b 100644
--- a/lib/buildkite/test_collector/rspec_plugin/reporter.rb
+++ b/lib/buildkite/test_collector/rspec_plugin/reporter.rb
@@ -40,6 +40,10 @@ def dump_summary(_notification)
       RSpec::Core::MultipleExceptionError
     ]
 
+    def blank?(string)
+      string.nil? || string.strip.empty?
+    end
+
     def failure_info(notification)
       failure_expanded = []
 
@@ -73,9 +77,9 @@ def failure_info(notification)
     def format_message_lines(message_lines)
       message_lines.map! { |l| strip_diff_colors(l) }
       # the first line is sometimes blank, depending on the error reported
-      message_lines.shift if message_lines.first.blank?
+      message_lines.shift if blank?(message_lines.first)
       # the last line is sometimes blank, depending on the error reported
-      message_lines.pop if message_lines.last.blank?
+      message_lines.pop if blank?(message_lines.last)
       message_lines
     end
 
diff --git a/lib/buildkite/test_collector/rspec_plugin/trace.rb b/lib/buildkite/test_collector/rspec_plugin/trace.rb
index 3a9b755..55415c5 100644
--- a/lib/buildkite/test_collector/rspec_plugin/trace.rb
+++ b/lib/buildkite/test_collector/rspec_plugin/trace.rb
@@ -32,7 +32,7 @@ def as_hash
         failure_reason: failure_reason,
         failure_expanded: failure_expanded,
         history: history,
-      ).with_indifferent_access.select { |_, value| !value.nil? }
+      ).select { |_, value| !value.nil? }
     end
 
     private
@@ -60,7 +60,7 @@ def file_name
     end
 
     def shared_example?
-      example.metadata[:shared_group_inclusion_backtrace].any?
+      !example.metadata[:shared_group_inclusion_backtrace].empty?
     end
 
     def shared_example_call_location
diff --git a/lib/buildkite/test_collector/test_links_plugin/formatter.rb b/lib/buildkite/test_collector/test_links_plugin/formatter.rb
index a3a4646..c6e9349 100644
--- a/lib/buildkite/test_collector/test_links_plugin/formatter.rb
+++ b/lib/buildkite/test_collector/test_links_plugin/formatter.rb
@@ -10,7 +10,7 @@ def initialize(output)
 
     def dump_failures(notification)
       # Do not display summary if no failed examples
-      return unless notification.failed_examples.present?
+      return if notification.failed_examples.empty?
 
       # Check if a Test Analytics token is set
       return unless Buildkite::TestCollector.api_token
diff --git a/lib/buildkite/test_collector/tracer.rb b/lib/buildkite/test_collector/tracer.rb
index c41a14a..bc4d3ed 100644
--- a/lib/buildkite/test_collector/tracer.rb
+++ b/lib/buildkite/test_collector/tracer.rb
@@ -43,7 +43,7 @@ def as_hash
           duration: end_at - start_at,
           detail: detail,
           children: children.map(&:as_hash),
-        }.with_indifferent_access
+        }
       end
     end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index aae93ad..69fa230 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "buildkite/test_collector"
+require "active_support/notifications"
 
 Dir["spec/support/**/*.rb"].each { |f| require File.expand_path(f) }