diff --git a/build_tools/services.rb b/build_tools/services.rb
index c5b9c50cfc2..8ffcb455354 100644
--- a/build_tools/services.rb
+++ b/build_tools/services.rb
@@ -9,10 +9,10 @@ class ServiceEnumerator
     MANIFEST_PATH = File.expand_path('../../services.json', __FILE__)
 
     # Minimum `aws-sdk-core` version for new gem builds
-    MINIMUM_CORE_VERSION = "3.241.4"
+    MINIMUM_CORE_VERSION = "3.243.1"
 
     # Minimum `aws-sdk-core` version for new S3 gem builds
-    MINIMUM_CORE_VERSION_S3 = "3.243.0"
+    MINIMUM_CORE_VERSION_S3 = "3.243.1"
 
     EVENTSTREAM_PLUGIN = "Aws::Plugins::EventStreamConfiguration"
 
diff --git a/gems/aws-sdk-core/CHANGELOG.md b/gems/aws-sdk-core/CHANGELOG.md
index a2d2f149b46..3309d5bbeda 100644
--- a/gems/aws-sdk-core/CHANGELOG.md
+++ b/gems/aws-sdk-core/CHANGELOG.md
@@ -1,6 +1,8 @@
 Unreleased Changes
 ------------------
 
+* Issue - Fix waiter error matcher to handle both boolean and boolean-string acceptors.
+
 3.243.0 (2026-03-05)
 ------------------
 
diff --git a/gems/aws-sdk-core/lib/aws-sdk-core/waiters/poller.rb b/gems/aws-sdk-core/lib/aws-sdk-core/waiters/poller.rb
index 654350f54b1..99801607921 100644
--- a/gems/aws-sdk-core/lib/aws-sdk-core/waiters/poller.rb
+++ b/gems/aws-sdk-core/lib/aws-sdk-core/waiters/poller.rb
@@ -97,8 +97,8 @@ def matches_status?(acceptor, response)
 
       def matches_error?(acceptor, response)
         case acceptor['expected']
-        when 'false' then response.error.nil?
-        when 'true' then !response.error.nil?
+        when 'false', false then response.error.nil?
+        when 'true', true then !response.error.nil?
         else
           response.error.is_a?(Aws::Errors::ServiceError) &&
             response.error.code == acceptor['expected'].delete('.')
diff --git a/gems/aws-sdk-core/spec/aws/waiters_spec.rb b/gems/aws-sdk-core/spec/aws/waiters_spec.rb
index acf59fbffb7..9ee5b42d0f1 100644
--- a/gems/aws-sdk-core/spec/aws/waiters_spec.rb
+++ b/gems/aws-sdk-core/spec/aws/waiters_spec.rb
@@ -221,8 +221,12 @@ module Waiters
           context 'expected is true' do
             it 'succeeds when matched with any error' do
               client.stub_responses(:waiter_operation, RuntimeError.new)
-              expect { client.wait_until(:error_matcher_with_true) }
-                .not_to raise_error
+              expect { client.wait_until(:error_matcher_with_true) }.not_to raise_error
+            end
+
+            it 'succeeds when matched with any error' do
+              client.stub_responses(:waiter_operation, RuntimeError.new)
+              expect { client.wait_until(:error_matcher_with_boolean_true) }.not_to raise_error
             end
           end
 
@@ -233,8 +237,12 @@ module Waiters
                 'ResourceNotFoundException',
                 { complex_object: { string_member: 'expected' } }
               )
-              expect { client.wait_until(:error_matcher_with_false) }
-                .not_to raise_error
+              expect { client.wait_until(:error_matcher_with_false) }.not_to raise_error
+            end
+
+            it 'succeeds when no error is received' do
+              client.stub_responses(:waiter_operation, complex_object: { string_member: 'expected' })
+              expect { client.wait_until(:error_matcher_with_boolean_false) }.not_to raise_error
             end
 
             it 'fails when matched' do
diff --git a/gems/aws-sdk-core/spec/fixtures/waiters/waiters.json b/gems/aws-sdk-core/spec/fixtures/waiters/waiters.json
index 9bb7b7386a2..e33399c3178 100644
--- a/gems/aws-sdk-core/spec/fixtures/waiters/waiters.json
+++ b/gems/aws-sdk-core/spec/fixtures/waiters/waiters.json
@@ -383,6 +383,30 @@
           "argument": "BooleanList"
         }
       ]
+    },
+    "ErrorMatcherWithBooleanTrue": {
+      "delay": 0,
+      "operation": "WaiterOperation",
+      "maxAttempts": 25,
+      "acceptors": [
+        {
+          "matcher": "error",
+          "expected": true,
+          "state": "success"
+        }
+      ]
+    },
+    "ErrorMatcherWithBooleanFalse": {
+      "delay": 0,
+      "operation": "WaiterOperation",
+      "maxAttempts": 25,
+      "acceptors": [
+        {
+          "matcher": "error",
+          "expected": false,
+          "state": "success"
+        }
+      ]
     }
   }
 }
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