diff --git a/src/ZB.MOM.WW.ScadaBridge.Commons/Interfaces/Protocol/AlarmCapableProtocols.cs b/src/ZB.MOM.WW.ScadaBridge.Commons/Interfaces/Protocol/AlarmCapableProtocols.cs
index e7bfc151..f837f6d3 100644
--- a/src/ZB.MOM.WW.ScadaBridge.Commons/Interfaces/Protocol/AlarmCapableProtocols.cs
+++ b/src/ZB.MOM.WW.ScadaBridge.Commons/Interfaces/Protocol/AlarmCapableProtocols.cs
@@ -6,8 +6,9 @@ namespace ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Protocol;
 /// mirror native alarms).
 ///
 /// The set MUST stay in sync with the protocols registered against an
-/// alarm-subscribable adapter in the DCL <c>DataConnectionFactory</c>: today the
-/// "OpcUa" adapter (<c>OpcUaDataConnection</c>) and the "MxGateway" adapter
+/// alarm-subscribable adapter in
+/// <c>DataConnectionLayer/DataConnectionFactory.cs</c>: today the "OpcUa" adapter
+/// (<c>OpcUaDataConnection</c>) and the "MxGateway" adapter
 /// (<c>MxGatewayDataConnection</c>) both implement
 /// <see cref="IAlarmSubscribableConnection"/>. The runtime decision is made in
 /// <c>DataConnectionActor</c> via <c>_adapter is IAlarmSubscribableConnection</c>;
@@ -21,7 +22,9 @@ public static class AlarmCapableProtocols
     /// <summary>
     /// Determines whether a data connection's protocol string resolves to an
     /// alarm-capable adapter (one implementing <see cref="IAlarmSubscribableConnection"/>).
-    /// Case-insensitive; <c>null</c>/blank is not alarm-capable.
+    /// Case-insensitive to match <c>DataConnectionFactory</c>'s own
+    /// <c>OrdinalIgnoreCase</c> protocol-key lookup; <c>null</c>/blank is not
+    /// alarm-capable.
     /// </summary>
     /// <param name="protocol">The data connection protocol string (e.g. "OpcUa").</param>
     /// <returns><c>true</c> when the protocol's adapter can subscribe native alarms; otherwise <c>false</c>.</returns>
diff --git a/src/ZB.MOM.WW.ScadaBridge.DeploymentManager/FlatteningPipeline.cs b/src/ZB.MOM.WW.ScadaBridge.DeploymentManager/FlatteningPipeline.cs
index 39ccbf68..df78fe6c 100644
--- a/src/ZB.MOM.WW.ScadaBridge.DeploymentManager/FlatteningPipeline.cs
+++ b/src/ZB.MOM.WW.ScadaBridge.DeploymentManager/FlatteningPipeline.cs
@@ -114,8 +114,14 @@ public class FlatteningPipeline : IFlatteningPipeline
 
         // Compute the alarm-capable connection-name set so the semantic validator
         // can gate native-alarm-source bindings. "Alarm-capable" matches the DCL
-        // runtime decision (DataConnectionActor: _adapter is IAlarmSubscribableConnection),
-        // mapped from the protocol string via the shared AlarmCapableProtocols helper.
+        // runtime decision (DataConnectionActor: _adapter is IAlarmSubscribableConnection);
+        // here we filter connections by alarm-capable protocol, then collect their names.
+        //
+        // StringComparer.Ordinal is intentional: connection names are stored and
+        // matched as authored throughout the pipeline (all other name-keyed
+        // dictionaries in FlatteningService and SemanticValidator use the same
+        // case-sensitive semantics). OrdinalIgnoreCase would be inconsistent with
+        // the rest of the binding-resolution path.
         var alarmCapableConnectionNames = dataConnections.Values
             .Where(c => AlarmCapableProtocols.IsAlarmCapable(c.Protocol))
             .Select(c => c.Name)
diff --git a/tests/ZB.MOM.WW.ScadaBridge.DeploymentManager.Tests/FlatteningPipelineNativeAlarmCapabilityTests.cs b/tests/ZB.MOM.WW.ScadaBridge.DeploymentManager.Tests/FlatteningPipelineNativeAlarmCapabilityTests.cs
index b0d6a4de..a49f35c3 100644
--- a/tests/ZB.MOM.WW.ScadaBridge.DeploymentManager.Tests/FlatteningPipelineNativeAlarmCapabilityTests.cs
+++ b/tests/ZB.MOM.WW.ScadaBridge.DeploymentManager.Tests/FlatteningPipelineNativeAlarmCapabilityTests.cs
@@ -83,6 +83,12 @@ public class FlatteningPipelineNativeAlarmCapabilityTests
     [Theory]
     [InlineData("OpcUa")]
     [InlineData("MxGateway")]
+    // Case variants: IsAlarmCapable uses OrdinalIgnoreCase, matching DataConnectionFactory's
+    // own OrdinalIgnoreCase protocol-key lookup; lock the contract with non-canonical casing.
+    [InlineData("OPCUA")]
+    [InlineData("opcua")]
+    [InlineData("mxgateway")]
+    [InlineData("MXGATEWAY")]
     public async Task FlattenAndValidate_NativeAlarmSourceOnAlarmCapableConnection_NoCapabilityError(string protocol)
     {
         Arrange(connectionName: "Boiler", connectionProtocol: protocol, boundConnectionName: "Boiler");