diff --git a/TransactionProcessing.MerchantFileProcessor/Reporting/OperationsDashboardService.cs b/TransactionProcessing.MerchantFileProcessor/Reporting/OperationsDashboardService.cs
index 798f5d2..6045f44 100644
--- a/TransactionProcessing.MerchantFileProcessor/Reporting/OperationsDashboardService.cs
+++ b/TransactionProcessing.MerchantFileProcessor/Reporting/OperationsDashboardService.cs
@@ -616,7 +616,7 @@ private static void AppendSummaryPanel(StringBuilder html, string title, IEnumer
         }
 
         html.AppendLine("      </dl>");
-        html.AppendLine("    </section>");
+        html.AppendLine(SectionEnd);
     }
 
     private static void AppendMerchantConfigPanel(StringBuilder html)
@@ -629,7 +629,7 @@ private static void AppendMerchantConfigPanel(StringBuilder html)
         html.AppendLine("        <li>SQLite is used for the local audit trail and status tables.</li>");
         html.AppendLine("        <li>Merchant schedules are interpreted in UTC and backed by the worker loop.</li>");
         html.AppendLine("      </ul>");
-        html.AppendLine("    </section>");
+        html.AppendLine(SectionEnd);
     }
 
     private static void AppendFileProfilesSection(StringBuilder html, IReadOnlyList<FileProfileRow> fileProfiles)
@@ -658,7 +658,7 @@ private static void AppendFileProfilesSection(StringBuilder html, IReadOnlyList<
 
         html.AppendLine(TableBodyEnd);
         html.AppendLine(TableEnd);
-        html.AppendLine("    </section>");
+        html.AppendLine(SectionEnd);
     }
 
     private static void AppendContractsSection(StringBuilder html, IReadOnlyList<ContractMappingRow> contracts)
@@ -684,7 +684,7 @@ private static void AppendContractsSection(StringBuilder html, IReadOnlyList<Con
 
         html.AppendLine(TableBodyEnd);
         html.AppendLine(TableEnd);
-        html.AppendLine("    </section>");
+        html.AppendLine(SectionEnd);
     }
 
     private static void AppendDocumentStart(StringBuilder html, string title, string subtitle)
diff --git a/TransactionProcessor.HealthChecksUI/TransactionProcessor.HealthChecksUI/Startup.cs b/TransactionProcessor.HealthChecksUI/TransactionProcessor.HealthChecksUI/Startup.cs
index d79e0b6..7f0b487 100644
--- a/TransactionProcessor.HealthChecksUI/TransactionProcessor.HealthChecksUI/Startup.cs
+++ b/TransactionProcessor.HealthChecksUI/TransactionProcessor.HealthChecksUI/Startup.cs
@@ -36,8 +36,9 @@ public void ConfigureServices(IServiceCollection services){
                                        }).AddInMemoryStorage();
         }
 
-        private HttpClientHandler ApiEndpointHttpHandler(IServiceProvider _)
+        private HttpClientHandler ApiEndpointHttpHandler(IServiceProvider serviceProvider)
         {
+            System.ArgumentNullException.ThrowIfNull(serviceProvider);
             return new HttpClientHandler();
         }