diff --git a/spec/integration/bulk_write_spec.rb b/spec/integration/bulk_write_spec.rb
index a586a7b3bb..a931f13945 100644
--- a/spec/integration/bulk_write_spec.rb
+++ b/spec/integration/bulk_write_spec.rb
@@ -21,7 +21,7 @@
   end
 
   context 'when bulk write needs to be split' do
-    let(:subscriber) { EventSubscriber.new }
+    let(:subscriber) { Mrss::EventSubscriber.new }
 
     let(:max_bson_size) { Mongo::Server::ConnectionBase::DEFAULT_MAX_BSON_OBJECT_SIZE }
 
diff --git a/spec/integration/change_stream_spec.rb b/spec/integration/change_stream_spec.rb
index d64efd49a6..3adada7e59 100644
--- a/spec/integration/change_stream_spec.rb
+++ b/spec/integration/change_stream_spec.rb
@@ -53,7 +53,7 @@ def clear_fail_point_before
       it 'raises an exception and does not attempt to resume' do
         change_stream
 
-        subscriber = EventSubscriber.new
+        subscriber = Mrss::EventSubscriber.new
         authorized_client.subscribe(Mongo::Monitoring::COMMAND, subscriber)
 
         expect do
@@ -523,7 +523,7 @@ def clear_fail_point_before
     let(:events) do
       start_after
 
-      subscriber = EventSubscriber.new
+      subscriber = Mrss::EventSubscriber.new
       authorized_client.subscribe(Mongo::Monitoring::COMMAND, subscriber)
       use_stream
 
@@ -582,7 +582,7 @@ def clear_fail_point_before
     let(:stream) { authorized_collection.watch }
 
     let(:events) do
-      subscriber = EventSubscriber.new
+      subscriber = Mrss::EventSubscriber.new
       authorized_client.subscribe(Mongo::Monitoring::COMMAND, subscriber)
       use_stream
       subscriber.succeeded_events.select { |e|
diff --git a/spec/integration/client_side_encryption/auto_encryption_bulk_writes_spec.rb b/spec/integration/client_side_encryption/auto_encryption_bulk_writes_spec.rb
index f13c3bffd7..b8792be684 100644
--- a/spec/integration/client_side_encryption/auto_encryption_bulk_writes_spec.rb
+++ b/spec/integration/client_side_encryption/auto_encryption_bulk_writes_spec.rb
@@ -11,7 +11,7 @@
   include_context 'define shared FLE helpers'
   include_context 'with local kms_providers'
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     new_local_client(
diff --git a/spec/integration/client_side_encryption/auto_encryption_command_monitoring_spec.rb b/spec/integration/client_side_encryption/auto_encryption_command_monitoring_spec.rb
index 8713c9c5d0..cef8a166a3 100644
--- a/spec/integration/client_side_encryption/auto_encryption_command_monitoring_spec.rb
+++ b/spec/integration/client_side_encryption/auto_encryption_command_monitoring_spec.rb
@@ -15,7 +15,7 @@
   include_context 'define shared FLE helpers'
   include_context 'with local kms_providers'
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
   let(:db_name) { 'auto_encryption' }
 
   let(:encryption_client) do
diff --git a/spec/integration/client_side_encryption/bson_size_limit_spec.rb b/spec/integration/client_side_encryption/bson_size_limit_spec.rb
index 14e0740b59..556248f3c3 100644
--- a/spec/integration/client_side_encryption/bson_size_limit_spec.rb
+++ b/spec/integration/client_side_encryption/bson_size_limit_spec.rb
@@ -11,7 +11,7 @@
 
     include_context 'define shared FLE helpers'
 
-    let(:subscriber) { EventSubscriber.new }
+    let(:subscriber) { Mrss::EventSubscriber.new }
 
     let(:client) do
       authorized_client.use('db')
diff --git a/spec/integration/client_side_encryption/data_key_spec.rb b/spec/integration/client_side_encryption/data_key_spec.rb
index 5254a9e749..7e89620cc0 100644
--- a/spec/integration/client_side_encryption/data_key_spec.rb
+++ b/spec/integration/client_side_encryption/data_key_spec.rb
@@ -11,7 +11,7 @@
 
     include_context 'define shared FLE helpers'
 
-    let(:subscriber) { EventSubscriber.new }
+    let(:subscriber) { Mrss::EventSubscriber.new }
 
     let(:client) do
       new_local_client(
diff --git a/spec/integration/command_monitoring_spec.rb b/spec/integration/command_monitoring_spec.rb
index 0cb61b40c9..7f0ec3578b 100644
--- a/spec/integration/command_monitoring_spec.rb
+++ b/spec/integration/command_monitoring_spec.rb
@@ -5,7 +5,7 @@
 
 describe 'Command monitoring' do
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.with(app_name: 'command monitoring spec').tap do |client|
diff --git a/spec/integration/command_spec.rb b/spec/integration/command_spec.rb
index 165d385fb0..9b3237df72 100644
--- a/spec/integration/command_spec.rb
+++ b/spec/integration/command_spec.rb
@@ -5,7 +5,7 @@
 
 describe 'Command' do
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   describe 'payload' do
     let(:server) { authorized_client.cluster.next_primary }
diff --git a/spec/integration/connection_spec.rb b/spec/integration/connection_spec.rb
index a3c7de1df4..6cea7563fa 100644
--- a/spec/integration/connection_spec.rb
+++ b/spec/integration/connection_spec.rb
@@ -50,7 +50,7 @@
 
       context 'with sdam event subscription' do
 
-        let(:subscriber) { EventSubscriber.new }
+        let(:subscriber) { Mrss::EventSubscriber.new }
         let(:client) do
           ClientRegistry.instance.global_client('authorized').with(app_name: 'connection_integration').tap do |client|
             client.subscribe(Mongo::Monitoring::SERVER_OPENING, subscriber)
diff --git a/spec/integration/cursor_reaping_spec.rb b/spec/integration/cursor_reaping_spec.rb
index 2ae347706d..e465434e91 100644
--- a/spec/integration/cursor_reaping_spec.rb
+++ b/spec/integration/cursor_reaping_spec.rb
@@ -21,7 +21,7 @@
   end
 =end
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/integration/get_more_spec.rb b/spec/integration/get_more_spec.rb
index c7070f54f6..6f53a141f5 100644
--- a/spec/integration/get_more_spec.rb
+++ b/spec/integration/get_more_spec.rb
@@ -7,7 +7,7 @@
   # https://jira.mongodb.org/browse/RUBY-1987
   min_server_fcv '3.2'
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/integration/heartbeat_events_spec.rb b/spec/integration/heartbeat_events_spec.rb
index f2d16849a8..08da6baf43 100644
--- a/spec/integration/heartbeat_events_spec.rb
+++ b/spec/integration/heartbeat_events_spec.rb
@@ -11,7 +11,7 @@ class HeartbeatEventsSpecTestException < StandardError; end
 
   clean_slate_for_all
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   before do
     Mongo::Monitoring::Global.subscribe(Mongo::Monitoring::SERVER_HEARTBEAT, subscriber)
diff --git a/spec/integration/map_reduce_spec.rb b/spec/integration/map_reduce_spec.rb
index 38afed6408..634d9e9cae 100644
--- a/spec/integration/map_reduce_spec.rb
+++ b/spec/integration/map_reduce_spec.rb
@@ -7,7 +7,7 @@
   let(:client) { authorized_client }
   let(:collection) { client['mr_integration'] }
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:find_options) { {} }
 
diff --git a/spec/integration/query_cache_spec.rb b/spec/integration/query_cache_spec.rb
index b7c4137c36..ce6363bdef 100644
--- a/spec/integration/query_cache_spec.rb
+++ b/spec/integration/query_cache_spec.rb
@@ -28,7 +28,7 @@
     SessionRegistry.instance.verify_sessions_ended!
   end
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/integration/query_cache_transactions_spec.rb b/spec/integration/query_cache_transactions_spec.rb
index 29d77763ba..aae9016644 100644
--- a/spec/integration/query_cache_transactions_spec.rb
+++ b/spec/integration/query_cache_transactions_spec.rb
@@ -23,7 +23,7 @@
   # leak sessions independently of the query cache. This will be resolved by
   # RUBY-2391.
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/integration/read_concern_spec.rb b/spec/integration/read_concern_spec.rb
index ea152b3704..bf313dfd50 100644
--- a/spec/integration/read_concern_spec.rb
+++ b/spec/integration/read_concern_spec.rb
@@ -7,7 +7,7 @@
   min_server_version '3.2'
 
   let(:subscriber) do
-    EventSubscriber.new
+    Mrss::EventSubscriber.new
   end
 
   let(:specified_read_concern) do
diff --git a/spec/integration/read_preference_spec.rb b/spec/integration/read_preference_spec.rb
index 68ae5b9107..ca46da81ea 100644
--- a/spec/integration/read_preference_spec.rb
+++ b/spec/integration/read_preference_spec.rb
@@ -16,7 +16,7 @@
     authorized_client.with(client_options)
   end
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   before do
     client.subscribe(Mongo::Monitoring::COMMAND, subscriber)
diff --git a/spec/integration/retryable_errors_spec.rb b/spec/integration/retryable_errors_spec.rb
index 187b1ad3c1..1cbf979919 100644
--- a/spec/integration/retryable_errors_spec.rb
+++ b/spec/integration/retryable_errors_spec.rb
@@ -7,7 +7,7 @@
   # Requirement for fail point
   min_server_fcv '4.0'
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client_options) do
     {}
diff --git a/spec/integration/sdam_error_handling_spec.rb b/spec/integration/sdam_error_handling_spec.rb
index e589937263..5c756d2653 100644
--- a/spec/integration/sdam_error_handling_spec.rb
+++ b/spec/integration/sdam_error_handling_spec.rb
@@ -18,7 +18,7 @@
   # shard cluster where multiple servers are equally eligible
   require_no_multi_mongos
 
-  let(:diagnostic_subscriber) { VerboseEventSubscriber.new }
+  let(:diagnostic_subscriber) { Mrss::VerboseEventSubscriber.new }
 
   let(:client) do
     new_local_client(SpecConfig.instance.addresses,
@@ -290,7 +290,7 @@
   describe 'when there is an error on monitoring connection' do
     clean_slate_for_all
 
-    let(:subscriber) { EventSubscriber.new }
+    let(:subscriber) { Mrss::EventSubscriber.new }
 
     let(:set_subscribers) do
       client.subscribe(Mongo::Monitoring::SERVER_DESCRIPTION_CHANGED, subscriber)
diff --git a/spec/integration/sdam_events_spec.rb b/spec/integration/sdam_events_spec.rb
index 8edb49e535..a59f7c923b 100644
--- a/spec/integration/sdam_events_spec.rb
+++ b/spec/integration/sdam_events_spec.rb
@@ -4,7 +4,7 @@
 require 'spec_helper'
 
 describe 'SDAM events' do
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   describe 'server closed event' do
     it 'is published when client is closed' do
diff --git a/spec/integration/sdam_prose_spec.rb b/spec/integration/sdam_prose_spec.rb
index 1487b4db53..8f85fd869c 100644
--- a/spec/integration/sdam_prose_spec.rb
+++ b/spec/integration/sdam_prose_spec.rb
@@ -11,7 +11,7 @@
     min_server_fcv '4.4'
     require_topology :single
 
-    let(:subscriber) { EventSubscriber.new }
+    let(:subscriber) { Mrss::EventSubscriber.new }
 
     let(:client) do
       new_local_client(SpecConfig.instance.addresses,
diff --git a/spec/integration/step_down_spec.rb b/spec/integration/step_down_spec.rb
index 7abcb7e6d2..b726c06d9c 100644
--- a/spec/integration/step_down_spec.rb
+++ b/spec/integration/step_down_spec.rb
@@ -32,7 +32,7 @@
     end
   end
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:test_client) do
     authorized_client_without_any_retries.with(server_selection_timeout: 20).tap do |client|
diff --git a/spec/integration/x509_auth_spec.rb b/spec/integration/x509_auth_spec.rb
index f7b697a979..c6c164b668 100644
--- a/spec/integration/x509_auth_spec.rb
+++ b/spec/integration/x509_auth_spec.rb
@@ -38,7 +38,7 @@
       "C=US,ST=New York,L=New York City,O=MongoDB,OU=x509,CN=localhost".freeze
     end
 
-    let(:subscriber) { EventSubscriber.new }
+    let(:subscriber) { Mrss::EventSubscriber.new }
 
     shared_examples 'authenticates successfully' do
       it 'authenticates successfully' do
diff --git a/spec/lite_spec_helper.rb b/spec/lite_spec_helper.rb
index b3ab77882f..9a408bfe77 100644
--- a/spec/lite_spec_helper.rb
+++ b/spec/lite_spec_helper.rb
@@ -77,7 +77,7 @@ module Mrss
 
 require 'mrss/lite_constraints'
 require 'support/matchers'
-require 'support/event_subscriber'
+require 'mrss/event_subscriber'
 require 'support/common_shortcuts'
 require 'support/client_registry'
 require 'support/client_registry_macros'
diff --git a/spec/mongo/auth/user/view_spec.rb b/spec/mongo/auth/user/view_spec.rb
index 135453a315..8a43e20c45 100644
--- a/spec/mongo/auth/user/view_spec.rb
+++ b/spec/mongo/auth/user/view_spec.rb
@@ -23,7 +23,7 @@
   shared_context 'testing write concern' do
 
     let(:subscriber) do
-      EventSubscriber.new
+      Mrss::EventSubscriber.new
     end
 
     let(:client) do
diff --git a/spec/mongo/bulk_write_spec.rb b/spec/mongo/bulk_write_spec.rb
index edc31c054a..4a213cb990 100644
--- a/spec/mongo/bulk_write_spec.rb
+++ b/spec/mongo/bulk_write_spec.rb
@@ -2106,7 +2106,7 @@
             require_no_multi_mongos
 
 
-            let(:subscriber) { EventSubscriber.new }
+            let(:subscriber) { Mrss::EventSubscriber.new }
 
             let(:client) do
               authorized_client_with_retry_writes.tap do |client|
diff --git a/spec/mongo/client_construction_spec.rb b/spec/mongo/client_construction_spec.rb
index e797788668..1d9237628b 100644
--- a/spec/mongo/client_construction_spec.rb
+++ b/spec/mongo/client_construction_spec.rb
@@ -6,7 +6,7 @@
 describe Mongo::Client do
   clean_slate
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   describe '.new' do
     context 'with scan: false' do
diff --git a/spec/mongo/client_spec.rb b/spec/mongo/client_spec.rb
index 6b2290a2a6..ee8c829250 100644
--- a/spec/mongo/client_spec.rb
+++ b/spec/mongo/client_spec.rb
@@ -635,7 +635,7 @@
         root_authorized_client.options.merge(heartbeat_frequency: 100, monitoring: true)
       end
 
-      let(:subscriber) { EventSubscriber.new }
+      let(:subscriber) { Mrss::EventSubscriber.new }
 
       let(:client) do
         ClientRegistry.instance.new_local_client(
diff --git a/spec/mongo/cluster_spec.rb b/spec/mongo/cluster_spec.rb
index c0b9c522bc..2c765e4f13 100644
--- a/spec/mongo/cluster_spec.rb
+++ b/spec/mongo/cluster_spec.rb
@@ -362,7 +362,7 @@
       end
 
       let(:monitoring) { Mongo::Monitoring.new }
-      let(:subscriber) { EventSubscriber.new }
+      let(:subscriber) { Mrss::EventSubscriber.new }
 
       it 'publishes server closed event once' do
         monitoring.subscribe(Mongo::Monitoring::SERVER_CLOSED, subscriber)
diff --git a/spec/mongo/collection/view/aggregation_spec.rb b/spec/mongo/collection/view/aggregation_spec.rb
index f5810121d4..46c836fe16 100644
--- a/spec/mongo/collection/view/aggregation_spec.rb
+++ b/spec/mongo/collection/view/aggregation_spec.rb
@@ -235,7 +235,7 @@
         { session: session }
       end
 
-      let(:subscriber) { EventSubscriber.new }
+      let(:subscriber) { Mrss::EventSubscriber.new }
 
       let(:client) do
         authorized_client.tap do |client|
diff --git a/spec/mongo/collection/view/map_reduce_spec.rb b/spec/mongo/collection/view/map_reduce_spec.rb
index 4ac3d77d68..d9b7fe427e 100644
--- a/spec/mongo/collection/view/map_reduce_spec.rb
+++ b/spec/mongo/collection/view/map_reduce_spec.rb
@@ -242,7 +242,7 @@
             Mongo::Collection::View.new(client[TEST_COLL], selector, view_options)
           end
 
-          let(:subscriber) { EventSubscriber.new }
+          let(:subscriber) { Mrss::EventSubscriber.new }
 
           let(:client) do
             authorized_client.tap do |client|
diff --git a/spec/mongo/collection_crud_spec.rb b/spec/mongo/collection_crud_spec.rb
index d3841565cb..6659e400e5 100644
--- a/spec/mongo/collection_crud_spec.rb
+++ b/spec/mongo/collection_crud_spec.rb
@@ -5,7 +5,7 @@
 
 describe Mongo::Collection do
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/mongo/collection_ddl_spec.rb b/spec/mongo/collection_ddl_spec.rb
index 9e4a8948e8..b3e31a2569 100644
--- a/spec/mongo/collection_ddl_spec.rb
+++ b/spec/mongo/collection_ddl_spec.rb
@@ -5,7 +5,7 @@
 
 describe Mongo::Collection do
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/mongo/collection_spec.rb b/spec/mongo/collection_spec.rb
index bd297317d4..819b6bc234 100644
--- a/spec/mongo/collection_spec.rb
+++ b/spec/mongo/collection_spec.rb
@@ -5,7 +5,7 @@
 
 describe Mongo::Collection do
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/mongo/cursor_spec.rb b/spec/mongo/cursor_spec.rb
index 0463d29a1d..2f3c6862de 100644
--- a/spec/mongo/cursor_spec.rb
+++ b/spec/mongo/cursor_spec.rb
@@ -438,7 +438,7 @@
   context 'when an implicit session is used' do
     min_server_fcv '3.6'
 
-    let(:subscriber) { EventSubscriber.new }
+    let(:subscriber) { Mrss::EventSubscriber.new }
 
     let(:subscribed_client) do
       authorized_client.tap do |client|
diff --git a/spec/mongo/database_spec.rb b/spec/mongo/database_spec.rb
index 7938a34a07..e27c451ff7 100644
--- a/spec/mongo/database_spec.rb
+++ b/spec/mongo/database_spec.rb
@@ -218,7 +218,7 @@
           described_class.new(client, SpecConfig.instance.test_db)
         end
 
-        let(:subscriber) { EventSubscriber.new }
+        let(:subscriber) { Mrss::EventSubscriber.new }
 
         let(:client) do
           authorized_client.tap do |client|
@@ -391,7 +391,7 @@
           described_class.new(client, SpecConfig.instance.test_db)
         end
 
-        let(:subscriber) { EventSubscriber.new }
+        let(:subscriber) { Mrss::EventSubscriber.new }
 
         let(:client) do
           authorized_client.tap do |client|
@@ -583,7 +583,7 @@
           described_class.new(client, SpecConfig.instance.test_db)
         end
 
-        let(:subscriber) { EventSubscriber.new }
+        let(:subscriber) { Mrss::EventSubscriber.new }
 
         let(:client) do
           authorized_client.tap do |client|
@@ -678,7 +678,7 @@
         client.start_session
       end
 
-      let(:subscriber) { EventSubscriber.new }
+      let(:subscriber) { Mrss::EventSubscriber.new }
 
       let(:client) do
         authorized_client.tap do |client|
@@ -969,7 +969,7 @@
           client.start_session
         end
 
-        let(:subscriber) { EventSubscriber.new }
+        let(:subscriber) { Mrss::EventSubscriber.new }
 
         let(:client) do
           root_authorized_client.tap do |client|
diff --git a/spec/mongo/index/view_spec.rb b/spec/mongo/index/view_spec.rb
index 1c1d4f6d0b..b20d9b35e0 100644
--- a/spec/mongo/index/view_spec.rb
+++ b/spec/mongo/index/view_spec.rb
@@ -266,7 +266,7 @@
           context 'on server versions >= 4.4' do
             min_server_fcv '4.4'
 
-            let(:subscriber) { EventSubscriber.new }
+            let(:subscriber) { Mrss::EventSubscriber.new }
 
             let(:client) do
               authorized_client.tap do |client|
@@ -932,7 +932,7 @@
       context 'on server versions >= 4.4' do
         min_server_fcv '4.4'
 
-        let(:subscriber) { EventSubscriber.new }
+        let(:subscriber) { Mrss::EventSubscriber.new }
 
         let(:client) do
           authorized_client.tap do |client|
diff --git a/spec/mongo/query_cache_spec.rb b/spec/mongo/query_cache_spec.rb
index 0ef3fe3b92..ac01826d35 100644
--- a/spec/mongo/query_cache_spec.rb
+++ b/spec/mongo/query_cache_spec.rb
@@ -14,7 +14,7 @@
     authorized_collection.delete_many
   end
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/mongo/server/connection_pool_spec.rb b/spec/mongo/server/connection_pool_spec.rb
index 1385aa4e20..8583f28a2e 100644
--- a/spec/mongo/server/connection_pool_spec.rb
+++ b/spec/mongo/server/connection_pool_spec.rb
@@ -602,7 +602,7 @@
        it 'raises an error and emits ConnectionCheckOutFailedEvent' do
         pool
 
-        subscriber = EventSubscriber.new
+        subscriber = Mrss::EventSubscriber.new
         client.subscribe(Mongo::Monitoring::CONNECTION_POOL, subscriber)
 
         subscriber.clear_events!
diff --git a/spec/mongo/session/session_pool_spec.rb b/spec/mongo/session/session_pool_spec.rb
index e96c2aeeb7..6d196dff0f 100644
--- a/spec/mongo/session/session_pool_spec.rb
+++ b/spec/mongo/session/session_pool_spec.rb
@@ -192,7 +192,7 @@
       pool.checkout
     end
 
-    let(:subscriber) { EventSubscriber.new }
+    let(:subscriber) { Mrss::EventSubscriber.new }
 
     let(:client) do
       authorized_client.tap do |client|
diff --git a/spec/runners/change_streams/test.rb b/spec/runners/change_streams/test.rb
index cfb19bb0f3..7d38a9ff50 100644
--- a/spec/runners/change_streams/test.rb
+++ b/spec/runners/change_streams/test.rb
@@ -89,7 +89,7 @@ def setup_test
 
         setup_fail_point(client)
 
-        @subscriber = EventSubscriber.new
+        @subscriber = Mrss::EventSubscriber.new
         client.subscribe(Mongo::Monitoring::COMMAND, @subscriber)
 
         @target = case @target_type
diff --git a/spec/runners/cmap.rb b/spec/runners/cmap.rb
index 30b13927e8..9085728411 100644
--- a/spec/runners/cmap.rb
+++ b/spec/runners/cmap.rb
@@ -33,7 +33,7 @@ class Spec
       # @return [ Mongo::ConnectionPool ] pool The connection pool to use for operations.
       attr_reader :pool
 
-      # @return [ EventSubscriber ] subscriber The subscriber receiving the CMAP events.
+      # @return [ Mrss::EventSubscriber ] subscriber The subscriber receiving the CMAP events.
       attr_reader :subscriber
 
       # Instantiate the new spec.
diff --git a/spec/runners/crud.rb b/spec/runners/crud.rb
index 7a2b9130e5..c0c1a7c651 100644
--- a/spec/runners/crud.rb
+++ b/spec/runners/crud.rb
@@ -96,7 +96,7 @@ def define_crud_spec_test_examples(spec, req = nil, &block)
       end
 
       let(:event_subscriber) do
-        EventSubscriber.new
+        Mrss::EventSubscriber.new
       end
 
       let(:verifier) { Mongo::CRUD::Verifier.new(test) }
diff --git a/spec/runners/transactions/test.rb b/spec/runners/transactions/test.rb
index c7714eb13a..49085697ce 100644
--- a/spec/runners/transactions/test.rb
+++ b/spec/runners/transactions/test.rb
@@ -141,11 +141,11 @@ def test_client
       end
 
       def command_subscriber
-        @command_subscriber ||= EventSubscriber.new
+        @command_subscriber ||= Mrss::EventSubscriber.new
       end
 
       def sdam_subscriber
-        @sdam_subscriber ||= EventSubscriber.new(name: 'sdam subscriber')
+        @sdam_subscriber ||= Mrss::EventSubscriber.new(name: 'sdam subscriber')
       end
 
       # Run the test.
diff --git a/spec/runners/unified/event_subscriber.rb b/spec/runners/unified/event_subscriber.rb
index 073b515a9a..42490b4a6e 100644
--- a/spec/runners/unified/event_subscriber.rb
+++ b/spec/runners/unified/event_subscriber.rb
@@ -1,11 +1,11 @@
 # frozen_string_literal: true
 # encoding: utf-8
 
-require 'support/event_subscriber'
+require 'mrss/event_subscriber'
 
 module Unified
 
-  class EventSubscriber < ::EventSubscriber
+  class EventSubscriber < Mrss::EventSubscriber
     def ignore_commands(command_names)
       @ignore_commands = command_names
     end
diff --git a/spec/shared b/spec/shared
index e489f0dc70..96871ae135 160000
--- a/spec/shared
+++ b/spec/shared
@@ -1 +1 @@
-Subproject commit e489f0dc706982576d004e61805b0d7c1e3b338e
+Subproject commit 96871ae1353e2229f9ebf839594e4eb76451c22b
diff --git a/spec/spec_tests/cmap_spec.rb b/spec/spec_tests/cmap_spec.rb
index bb0bdc043c..b164866558 100644
--- a/spec/spec_tests/cmap_spec.rb
+++ b/spec/spec_tests/cmap_spec.rb
@@ -40,7 +40,7 @@
     context("#{spec.description} (#{file.sub(%r'.*/data/cmap/', '')})") do
 
       before do
-        subscriber = EventSubscriber.new
+        subscriber = Mrss::EventSubscriber.new
 
         monitoring = Mongo::Monitoring.new(monitoring: false)
         monitoring.subscribe(Mongo::Monitoring::CONNECTION_POOL, subscriber)
diff --git a/spec/spec_tests/command_monitoring_spec.rb b/spec/spec_tests/command_monitoring_spec.rb
index 2fa235c0f6..44fcbd832b 100644
--- a/spec/spec_tests/command_monitoring_spec.rb
+++ b/spec/spec_tests/command_monitoring_spec.rb
@@ -24,7 +24,7 @@
           end
 
           let(:subscriber) do
-            EventSubscriber.new
+            Mrss::EventSubscriber.new
           end
 
           let(:monitoring) do
@@ -54,7 +54,7 @@
 
   def check_event(subscriber, index, expectation)
     subscriber.all_events.length.should > index
-    # TODO move this filtering into EventSubscriber
+    # TODO move this filtering into Mrss::EventSubscriber
     events = subscriber.all_events.reject do |event|
       (
         event.is_a?(Mongo::Monitoring::Event::CommandStarted) ||
diff --git a/spec/spec_tests/sdam_monitoring_spec.rb b/spec/spec_tests/sdam_monitoring_spec.rb
index 6c4d65f0cb..e6517effe8 100644
--- a/spec/spec_tests/sdam_monitoring_spec.rb
+++ b/spec/spec_tests/sdam_monitoring_spec.rb
@@ -16,7 +16,7 @@
     context("#{spec.description} (#{file.sub(%r'.*/data/sdam_monitoring/', '')})") do
 
       before(:all) do
-        @subscriber = PhasedEventSubscriber.new
+        @subscriber = Mrss::PhasedEventSubscriber.new
         sdam_proc = lambda do |client|
           client.subscribe(Mongo::Monitoring::SERVER_OPENING, @subscriber)
           client.subscribe(Mongo::Monitoring::SERVER_CLOSED, @subscriber)
diff --git a/spec/support/event_subscriber.rb b/spec/support/event_subscriber.rb
deleted file mode 100644
index 5513b03135..0000000000
--- a/spec/support/event_subscriber.rb
+++ /dev/null
@@ -1,221 +0,0 @@
-# frozen_string_literal: true
-# encoding: utf-8
-
-# Test event subscriber.
-#
-# @since 2.5.0
-class EventSubscriber
-
-  # The mappings of event names to types.
-  #
-  # @since 2.4.0
-  MAPPINGS = {
-    'topology_opening_event' => Mongo::Monitoring::Event::TopologyOpening,
-    'topology_description_changed_event' => Mongo::Monitoring::Event::TopologyChanged,
-    'topology_closed_event' => Mongo::Monitoring::Event::TopologyClosed,
-    'server_opening_event' => Mongo::Monitoring::Event::ServerOpening,
-    'server_description_changed_event' => Mongo::Monitoring::Event::ServerDescriptionChanged,
-    'server_closed_event' => Mongo::Monitoring::Event::ServerClosed
-  }.freeze
-
-  # All events.
-  attr_reader :all_events
-
-  # The started events.
-  #
-  # @since 2.5.0
-  attr_reader :started_events
-
-  # The succeeded events.
-  #
-  # @since 2.5.0
-  attr_reader :succeeded_events
-
-  # The failed events.
-  #
-  # @since 2.5.0
-  attr_reader :failed_events
-
-  attr_reader :published_events
-
-  # @param [ String ] name Optional name for the event subscriber.
-  def initialize(name: nil)
-    @mutex = Mutex.new
-    clear_events!
-    @name = name
-  end
-
-  def to_s
-    %Q`#<EventSubscriber:#{@name ? "\"#{@name}\"" : '%x' % object_id} \
-started=#{started_events.length} \
-succeeded=#{succeeded_events.length} \
-failed=#{failed_events.length} \
-published=#{published_events.length}>`
-  end
-
-  alias :inspect :to_s
-
-  # Event retrieval
-
-  def select_started_events(cls)
-    started_events.select do |event|
-      event.is_a?(cls)
-    end
-  end
-
-  def select_succeeded_events(cls)
-    succeeded_events.select do |event|
-      event.is_a?(cls)
-    end
-  end
-
-  def select_completed_events(*classes)
-    (succeeded_events + failed_events).select do |event|
-      classes.any? { |c| c === event }
-    end
-  end
-
-  def select_published_events(cls)
-    published_events.select do |event|
-      event.is_a?(cls)
-    end
-  end
-
-  # Filters command started events for the specified command name.
-  def command_started_events(command_name)
-    started_events.select do |event|
-      event.command[command_name]
-    end
-  end
-
-  def non_auth_command_started_events
-    started_events.reject do |event|
-      %w(authenticate getnonce saslSstart saslContinue).any? do |cmd|
-        event.command[cmd]
-      end
-    end
-  end
-
-  # Locates command stated events for the specified command name,
-  # asserts that there is exactly one such event, and returns it.
-  def single_command_started_event(command_name, include_auth: false)
-    events = if include_auth
-      started_events
-    else
-      non_auth_command_started_events
-    end
-    events.select! do |event|
-      event.command[command_name]
-    end
-    if events.length != 1
-      raise "Expected a single #{command_name} event but we have #{events.length}"
-    end
-    events.first
-  end
-
-  # Get the first succeeded event published for the name, and then delete it.
-  #
-  # @param [ String ] name The event name.
-  #
-  # @return [ Event ] The matching event.
-  def first_event(name)
-    cls = MAPPINGS[name]
-    if cls.nil?
-      raise ArgumentError, "Bogus event name #{name}"
-    end
-    matching = succeeded_events.find do |event|
-      cls === event
-    end
-    succeeded_events.delete(matching)
-    matching
-  end
-
-  # Event recording
-
-  # Cache the started event.
-  #
-  # @param [ Event ] event The event.
-  #
-  # @since 2.5.0
-  def started(event)
-    @mutex.synchronize do
-      started_events << event
-      all_events << event
-    end
-  end
-
-  # Cache the succeeded event.
-  #
-  # @param [ Event ] event The event.
-  #
-  # @since 2.5.0
-  def succeeded(event)
-    @mutex.synchronize do
-      succeeded_events << event
-      all_events << event
-    end
-  end
-
-  # Cache the failed event.
-  #
-  # @param [ Event ] event The event.
-  #
-  # @since 2.5.0
-  def failed(event)
-    @mutex.synchronize do
-      failed_events << event
-      all_events << event
-    end
-  end
-
-  def published(event)
-    @mutex.synchronize do
-      published_events << event
-      all_events << event
-    end
-  end
-
-  # Clear all cached events.
-  #
-  # @since 2.5.1
-  def clear_events!
-    @all_events = []
-    @started_events = []
-    @succeeded_events = []
-    @failed_events = []
-    @published_events = []
-    self
-  end
-end
-
-# Only handles succeeded events correctly.
-class PhasedEventSubscriber < EventSubscriber
-  def initialize
-    super
-    @phase_events = {}
-  end
-
-  def phase_finished(phase_index)
-    @phase_events[phase_index] = succeeded_events
-    @succeeded_events = []
-  end
-
-  def phase_events(phase_index)
-    @phase_events[phase_index]
-  end
-
-  def event_count
-    @phase_events.inject(0) do |sum, event|
-      sum + event.length
-    end
-  end
-end
-
-class VerboseEventSubscriber < EventSubscriber
-  %w(started succeeded failed published).each do |meth|
-    define_method(meth) do |event|
-      puts event.summary
-      super(event)
-    end
-  end
-end
diff --git a/spec/support/shared/session.rb b/spec/support/shared/session.rb
index ad016d27f8..d48d4f0070 100644
--- a/spec/support/shared/session.rb
+++ b/spec/support/shared/session.rb
@@ -185,7 +185,7 @@
 
 shared_examples 'an operation supporting causally consistent reads' do
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
@@ -622,7 +622,7 @@
     client.start_session
   end
 
-  let(:subscriber) { EventSubscriber.new }
+  let(:subscriber) { Mrss::EventSubscriber.new }
 
   let(:client) do
     authorized_client.tap do |client|
diff --git a/spec/support/utils.rb b/spec/support/utils.rb
index f47d12eb1f..84b8ff6466 100644
--- a/spec/support/utils.rb
+++ b/spec/support/utils.rb
@@ -556,7 +556,7 @@ def match_with_type?(expected, actual)
   # command event published, asserts the command event published has the
   # specified command name, and returns the published event.
   module_function def get_command_event(client, command_name, include_auth: false)
-    subscriber = EventSubscriber.new
+    subscriber = Mrss::EventSubscriber.new
     client.subscribe(Mongo::Monitoring::COMMAND, subscriber)
     begin
       yield client