diff --git a/spec/statesman/adapters/active_record_queries_spec.rb b/spec/statesman/adapters/active_record_queries_spec.rb
index 685734eb..e57dc9e6 100644
--- a/spec/statesman/adapters/active_record_queries_spec.rb
+++ b/spec/statesman/adapters/active_record_queries_spec.rb
@@ -254,7 +254,7 @@ def self.initial_state; end
       end
 
       it "does not raise an error" do
-        expect { check_missing_methods! }.to_not raise_exception(NotImplementedError)
+        expect { check_missing_methods! }.to_not raise_exception
       end
     end
 
diff --git a/spec/statesman/adapters/active_record_spec.rb b/spec/statesman/adapters/active_record_spec.rb
index f82b0a9d..0cb7d42d 100644
--- a/spec/statesman/adapters/active_record_spec.rb
+++ b/spec/statesman/adapters/active_record_spec.rb
@@ -112,7 +112,7 @@
   end
 
   describe "#create" do
-    subject { -> { create } }
+    subject(:transition) { create }
 
     let!(:adapter) do
       described_class.new(MyActiveRecordModelTransition, model, observer)
@@ -173,19 +173,17 @@
           end
         end
 
-        it { is_expected.to raise_exception(ActiveRecord::RecordNotUnique) }
+        it { expect { transition }.to raise_exception(ActiveRecord::RecordNotUnique) }
       end
 
       context "other errors" do
         let(:error) { StandardError }
 
-        it { is_expected.to raise_exception(StandardError) }
+        it { expect { transition }.to raise_exception(StandardError) }
       end
     end
 
     describe "updating the most_recent column" do
-      subject { create }
-
       context "with no previous transition" do
         its(:most_recent) { is_expected.to eq(true) }
       end
diff --git a/spec/statesman/adapters/shared_examples.rb b/spec/statesman/adapters/shared_examples.rb
index 837ddb50..67a3bcc8 100644
--- a/spec/statesman/adapters/shared_examples.rb
+++ b/spec/statesman/adapters/shared_examples.rb
@@ -30,14 +30,14 @@
   end
 
   describe "#create" do
-    subject { -> { create } }
+    subject(:transition) { create }
 
     let(:from) { :x }
     let(:to) { :y }
     let(:there) { :z }
     let(:create) { adapter.create(from, to) }
 
-    it { is_expected.to change(adapter.history, :count).by(1) }
+    it { expect { transition }.to change(adapter.history, :count).by(1) }
 
     context "the new transition" do
       subject(:instance) { create }
diff --git a/spec/statesman/machine_spec.rb b/spec/statesman/machine_spec.rb
index d8b748b5..04842fb8 100644
--- a/spec/statesman/machine_spec.rb
+++ b/spec/statesman/machine_spec.rb
@@ -28,7 +28,7 @@
   end
 
   describe ".remove_state" do
-    subject(:remove_state) { -> { machine.remove_state(:x) } }
+    subject(:remove_state) { machine.remove_state(:x) }
 
     before do
       machine.class_eval do
@@ -39,7 +39,7 @@
     end
 
     it "removes the state" do
-      expect(remove_state).
+      expect { remove_state }.
         to change(machine, :states).
         from(match_array(%w[x y z])).
         to(%w[y z])
@@ -49,7 +49,7 @@
       before { machine.transition from: :x, to: :y }
 
       it "removes the transition" do
-        expect(remove_state).
+        expect { remove_state }.
           to change(machine, :successors).
           from({ "x" => ["y"] }).
           to({})
@@ -59,7 +59,7 @@
         before { machine.transition from: :x, to: :z }
 
         it "removes all transitions" do
-          expect(remove_state).
+          expect { remove_state }.
             to change(machine, :successors).
             from({ "x" => %w[y z] }).
             to({})
@@ -71,7 +71,7 @@
       before { machine.transition from: :y, to: :x }
 
       it "removes the transition" do
-        expect(remove_state).
+        expect { remove_state }.
           to change(machine, :successors).
           from({ "y" => ["x"] }).
           to({})
@@ -81,7 +81,7 @@
         before { machine.transition from: :z, to: :x }
 
         it "removes all transitions" do
-          expect(remove_state).
+          expect { remove_state }.
             to change(machine, :successors).
             from({ "y" => ["x"], "z" => ["x"] }).
             to({})
@@ -104,7 +104,7 @@
       end
 
       it "removes the guard" do
-        expect(remove_state).
+        expect { remove_state }.
           to change(machine, :callbacks).
           from(a_hash_including(guards: match_array(guards))).
           to(a_hash_including(guards: []))
@@ -125,7 +125,7 @@
       end
 
       it "removes the guard" do
-        expect(remove_state).
+        expect { remove_state }.
           to change(machine, :callbacks).
           from(a_hash_including(guards: match_array(guards))).
           to(a_hash_including(guards: []))
diff --git a/statesman.gemspec b/statesman.gemspec
index 7e350065..5dea7a16 100644
--- a/statesman.gemspec
+++ b/statesman.gemspec
@@ -32,7 +32,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "rspec", "~> 3.1"
   spec.add_development_dependency "rspec-github", "~> 2.4.0"
   spec.add_development_dependency "rspec-its", "~> 1.1"
-  spec.add_development_dependency "rspec-rails", "~> 3.1"
+  spec.add_development_dependency "rspec-rails", "~> 6.0"
   spec.add_development_dependency "sqlite3", "~> 1.6.1"
   spec.add_development_dependency "timecop", "~> 0.9.1"