diff --git a/src/languageFeatures.ts b/src/languageFeatures.ts
index 1ea08991..da5e4207 100644
--- a/src/languageFeatures.ts
+++ b/src/languageFeatures.ts
@@ -181,6 +181,7 @@ export class DiagnosticsAdapter extends Adapter {
 			}
 			const markers = diagnostics
 				.reduce((p, c) => c.concat(p), [])
+				.filter(d => (this._defaults.getDiagnosticsOptions().diagnosticCodesToIgnore || []).indexOf(d.code) === -1)
 				.map(d => this._convertDiagnostics(resource, d));
 
 			monaco.editor.setModelMarkers(monaco.editor.getModel(resource), this._selector, markers);
@@ -201,7 +202,8 @@ export class DiagnosticsAdapter extends Adapter {
 			endColumn,
 			message: flattenDiagnosticMessageText(diag.messageText, '\n'),
 			code: diag.code.toString(),
-			relatedInformation: this._convertRelatedInformation(resource, diag.relatedInformation)
+			tags: diag.reportsUnnecessary ? [monaco.MarkerTag.Unnecessary] : [],
+			relatedInformation: this._convertRelatedInformation(resource, diag.relatedInformation),
 		};
 	}
 
diff --git a/src/monaco.d.ts b/src/monaco.d.ts
index 8aa58804..7d50e7ab 100644
--- a/src/monaco.d.ts
+++ b/src/monaco.d.ts
@@ -129,6 +129,7 @@ declare module monaco.languages.typescript {
         noSemanticValidation?: boolean;
         noSyntaxValidation?: boolean;
         noSuggestionDiagnostics?: boolean;
+        diagnosticCodesToIgnore?: number[];
     }
 
     export interface LanguageServiceDefaults {