diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 837bb4cc..4a76c67d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -6,9 +6,10 @@ jobs:
     name: Test (Ruby ${{ matrix.ruby }}, ${{ matrix.os }})
     runs-on: ${{ matrix.os }}-latest
     strategy:
+      fail-fast: false
       matrix:
         os: [ ubuntu ]
-        ruby: [ '2.4', '2.5', '2.6', '2.7', '3.0', '3.1', '3.2', '3.3' ]
+        ruby: [ '2.4', '2.5', '2.6', '2.7', '3.0', '3.1', '3.2', '3.3', '3.4' ]
         include:
           - os: macos
             ruby: '2.7'
diff --git a/lib/stack_master/test_driver/cloud_formation.rb b/lib/stack_master/test_driver/cloud_formation.rb
index db525baf..66cb0dbf 100644
--- a/lib/stack_master/test_driver/cloud_formation.rb
+++ b/lib/stack_master/test_driver/cloud_formation.rb
@@ -1,3 +1,4 @@
+require 'ostruct'
 require 'securerandom'
 
 module StackMaster
diff --git a/stack_master.gemspec b/stack_master.gemspec
index 251eafda..5d803c09 100644
--- a/stack_master.gemspec
+++ b/stack_master.gemspec
@@ -33,6 +33,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "cucumber"
   spec.add_development_dependency "aruba"
   spec.add_development_dependency "timecop"
+  spec.add_development_dependency "ostruct"
   spec.add_dependency "os"
   spec.add_dependency "ruby-progressbar"
   spec.add_dependency "commander", ">= 4.6.0", "< 6"