diff --git a/Gemfile.activerecord-6.1.lock b/Gemfile.activerecord-6.1.lock
index 02d7f87..7fb7ddf 100644
--- a/Gemfile.activerecord-6.1.lock
+++ b/Gemfile.activerecord-6.1.lock
@@ -1,11 +1,11 @@
 PATH
   remote: .
   specs:
-    switchman-inst-jobs (4.0.15)
+    switchman-inst-jobs (4.0.16)
       inst-jobs (>= 2.4.9, < 4.0)
       parallel (>= 1.19)
       railties (>= 6.1, < 7.2)
-      switchman (~> 3.1)
+      switchman (~> 3.1, >= 3.5.14)
 
 GEM
   remote: https://rubygems.org/
@@ -82,8 +82,12 @@ GEM
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
     method_source (1.0.0)
+    mini_portile2 (2.8.4)
     minitest (5.20.0)
     newrelic_rpm (9.2.2)
+    nokogiri (1.15.4)
+      mini_portile2 (~> 2.8.2)
+      racc (~> 1.4)
     nokogiri (1.15.4-aarch64-linux)
       racc (~> 1.4)
     nokogiri (1.15.4-arm64-darwin)
@@ -185,7 +189,7 @@ GEM
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
-    switchman (3.5.13)
+    switchman (3.5.14)
       activerecord (>= 6.1.4, < 7.2)
       guardrail (~> 3.0.1)
       parallel (~> 1.22)
@@ -199,6 +203,7 @@ GEM
 PLATFORMS
   aarch64-linux
   arm64-darwin
+  ruby
   x86_64-darwin
   x86_64-linux
 
diff --git a/Gemfile.activerecord-7.0.lock b/Gemfile.activerecord-7.0.lock
index af6e79a..a71d0ac 100644
--- a/Gemfile.activerecord-7.0.lock
+++ b/Gemfile.activerecord-7.0.lock
@@ -1,11 +1,11 @@
 PATH
   remote: .
   specs:
-    switchman-inst-jobs (4.0.15)
+    switchman-inst-jobs (4.0.16)
       inst-jobs (>= 2.4.9, < 4.0)
       parallel (>= 1.19)
       railties (>= 6.1, < 7.2)
-      switchman (~> 3.1)
+      switchman (~> 3.1, >= 3.5.14)
 
 GEM
   remote: https://rubygems.org/
@@ -81,8 +81,12 @@ GEM
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
     method_source (1.0.0)
+    mini_portile2 (2.8.4)
     minitest (5.20.0)
     newrelic_rpm (9.2.2)
+    nokogiri (1.15.4)
+      mini_portile2 (~> 2.8.2)
+      racc (~> 1.4)
     nokogiri (1.15.4-aarch64-linux)
       racc (~> 1.4)
     nokogiri (1.15.4-arm64-darwin)
@@ -185,7 +189,7 @@ GEM
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
-    switchman (3.5.13)
+    switchman (3.5.14)
       activerecord (>= 6.1.4, < 7.2)
       guardrail (~> 3.0.1)
       parallel (~> 1.22)
@@ -199,6 +203,7 @@ GEM
 PLATFORMS
   aarch64-linux
   arm64-darwin
+  ruby
   x86_64-darwin
   x86_64-linux
 
diff --git a/Gemfile.lock b/Gemfile.lock
index 549634e..4a6da6e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,11 +1,11 @@
 PATH
   remote: .
   specs:
-    switchman-inst-jobs (4.0.15)
+    switchman-inst-jobs (4.0.16)
       inst-jobs (>= 2.4.9, < 4.0)
       parallel (>= 1.19)
       railties (>= 6.1, < 7.2)
-      switchman (~> 3.1)
+      switchman (~> 3.1, >= 3.5.14)
 
 GEM
   remote: https://rubygems.org/
@@ -97,9 +97,13 @@ GEM
       crass (~> 1.0.2)
       nokogiri (>= 1.12.0)
     method_source (1.0.0)
+    mini_portile2 (2.8.4)
     minitest (5.20.0)
     mutex_m (0.1.2)
     newrelic_rpm (9.2.2)
+    nokogiri (1.15.4)
+      mini_portile2 (~> 2.8.2)
+      racc (~> 1.4)
     nokogiri (1.15.4-aarch64-linux)
       racc (~> 1.4)
     nokogiri (1.15.4-arm64-darwin)
@@ -215,7 +219,7 @@ GEM
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.4)
     stringio (3.0.8)
-    switchman (3.5.13)
+    switchman (3.5.14)
       activerecord (>= 6.1.4, < 7.2)
       guardrail (~> 3.0.1)
       parallel (~> 1.22)
@@ -231,6 +235,7 @@ GEM
 PLATFORMS
   aarch64-linux
   arm64-darwin
+  ruby
   x86_64-darwin
   x86_64-linux
 
diff --git a/lib/switchman_inst_jobs/delayed/pool.rb b/lib/switchman_inst_jobs/delayed/pool.rb
index aa4dd64..74349b7 100644
--- a/lib/switchman_inst_jobs/delayed/pool.rb
+++ b/lib/switchman_inst_jobs/delayed/pool.rb
@@ -3,8 +3,17 @@
 module SwitchmanInstJobs
   module Delayed
     module Pool
+      def initialize(*)
+        super
+
+        raise "Cannot run jobs cross-region" unless shards.all?(&:in_current_region?)
+      end
+
       def unlock_orphaned_jobs(worker = nil, pid = nil)
         if worker
+          # this is just a failsafe; it shouldn't be possible
+          return unless worker.shard.in_current_region?
+
           shards = [worker.shard]
         else
           # Since we're not unlocking for a specific worker, look through
@@ -19,13 +28,18 @@ def unlock_orphaned_jobs(worker = nil, pid = nil)
           # We purposely don't .compact to remove nils here, since if any
           # workers are on the default jobs shard we want to unlock against
           # that shard too.
-          shard_ids = @config[:workers].pluck(:shard).uniq
-          shards = shard_ids.map { |shard_id| ::Delayed::Worker.shard(shard_id) }
+
+          shards = self.shards.select(&:in_current_region?)
         end
         ::Switchman::Shard.with_each_shard(shards, [::Delayed::Backend::ActiveRecord::AbstractJob]) do
           super
         end
       end
+
+      def shards
+        shard_ids = @config[:workers].pluck(:shard).uniq
+        shard_ids.map { |shard_id| ::Delayed::Worker.shard(shard_id) }
+      end
     end
   end
 end
diff --git a/lib/switchman_inst_jobs/delayed/worker.rb b/lib/switchman_inst_jobs/delayed/worker.rb
index 5201ce5..674acc2 100644
--- a/lib/switchman_inst_jobs/delayed/worker.rb
+++ b/lib/switchman_inst_jobs/delayed/worker.rb
@@ -10,6 +10,9 @@ def self.prepended(base)
       def initialize(options = {})
         # have to initialize this first, so #shard works
         @config = options
+        # this shouldn't be possible because of the pool check, but just in case
+        raise "Cannot run jobs cross-region" unless shard.in_current_region?
+
         ::Delayed::Worker::HealthCheck.munge_service_name(shard) do
           super
           # ensure we get our own copy of the munged config
diff --git a/lib/switchman_inst_jobs/version.rb b/lib/switchman_inst_jobs/version.rb
index ff566c3..b5c60f8 100644
--- a/lib/switchman_inst_jobs/version.rb
+++ b/lib/switchman_inst_jobs/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module SwitchmanInstJobs
-  VERSION = "4.0.15"
+  VERSION = "4.0.16"
 end
diff --git a/spec/lib/switchman_inst_jobs/delayed/pool_spec.rb b/spec/lib/switchman_inst_jobs/delayed/pool_spec.rb
index c0a2b5b..88c6e4f 100644
--- a/spec/lib/switchman_inst_jobs/delayed/pool_spec.rb
+++ b/spec/lib/switchman_inst_jobs/delayed/pool_spec.rb
@@ -7,13 +7,20 @@
   let(:worker) { Delayed::Worker.new(worker_max_job_count: 1, shard: shard.id) }
 
   describe "pools" do
+    it "prevents creation of pools with workers in other regions" do
+      expect(Switchman::Shard).to receive(:lookup).with(shard.id).and_return(shard)
+      expect(shard).to receive(:in_current_region?).and_return(false)
+
+      expect { Delayed::Pool.new({ workers: [{ shard: shard.id }] }) }.to raise_error("Cannot run jobs cross-region")
+    end
+
     it "should unlock against the worker's shard" do
       allow(Delayed::Job).to receive(:unlock_orphaned_jobs) do
         expect(Switchman::Shard.current(Delayed::Backend::ActiveRecord::AbstractJob))
           .to eq Switchman::Shard.default.delayed_jobs_shard
         0
       end
-      Delayed::Pool.new({}).send(
+      Delayed::Pool.new({ workers: [] }).send(
         :unlock_orphaned_jobs, Delayed::Worker.new, 1234
       )
 
@@ -21,11 +28,11 @@
         expect(Switchman::Shard.current(Delayed::Backend::ActiveRecord::AbstractJob)).to eq shard
         0
       end
-      Delayed::Pool.new({}).send(:unlock_orphaned_jobs, worker, 1234)
+      Delayed::Pool.new({ workers: [] }).send(:unlock_orphaned_jobs, worker, 1234)
     end
 
     it "should unlock against all configured shards" do
-      pool = Delayed::Pool.new({})
+      pool = Delayed::Pool.new({ workers: [] })
       pool.instance_variable_set(
         :@config,
         workers: [
diff --git a/spec/lib/switchman_inst_jobs/delayed/worker_spec.rb b/spec/lib/switchman_inst_jobs/delayed/worker_spec.rb
index bf3dc90..3f0a8f3 100644
--- a/spec/lib/switchman_inst_jobs/delayed/worker_spec.rb
+++ b/spec/lib/switchman_inst_jobs/delayed/worker_spec.rb
@@ -7,6 +7,12 @@
   let(:worker) { Delayed::Worker.new(worker_max_job_count: 1, shard: shard.id) }
 
   describe "workers" do
+    it "doesn't allow workers to be created for shards in other regions" do
+      expect(Switchman::Shard).to receive(:lookup).with(shard.id).and_return(shard)
+      expect(shard).to receive(:in_current_region?).and_return(false)
+      expect { worker }.to raise_error("Cannot run jobs cross-region")
+    end
+
     it "should activate the jobs shard when calling run" do
       expect(Delayed::Job).to receive(:get_and_lock_next_available).once do
         expect(Switchman::Shard.current(Delayed::Backend::ActiveRecord::AbstractJob)).to eq shard
diff --git a/switchman-inst-jobs.gemspec b/switchman-inst-jobs.gemspec
index a90db12..49e162f 100644
--- a/switchman-inst-jobs.gemspec
+++ b/switchman-inst-jobs.gemspec
@@ -26,7 +26,7 @@ Gem::Specification.new do |s|
   s.add_dependency "inst-jobs", ">= 2.4.9", "< 4.0"
   s.add_dependency "parallel", ">= 1.19"
   s.add_dependency "railties", ">= 6.1", "< 7.2"
-  s.add_dependency "switchman", "~> 3.1"
+  s.add_dependency "switchman", "~> 3.1", ">= 3.5.14"
 
   s.add_development_dependency "bundler"
   s.add_development_dependency "byebug"