diff --git a/editors/code/src/test/utils/diagnotics/rust.test.ts b/editors/code/src/test/utils/diagnotics/rust.test.ts
index 7fb003fe21..327d15046f 100644
--- a/editors/code/src/test/utils/diagnotics/rust.test.ts
+++ b/editors/code/src/test/utils/diagnotics/rust.test.ts
@@ -50,7 +50,7 @@ describe('mapRustDiagnosticToVsCode', () => {
             ].join('\n')
         );
         assert.strictEqual(diagnostic.code, 'E0053');
-        assert.strictEqual(diagnostic.tags, undefined);
+        assert.deepStrictEqual(diagnostic.tags, []);
 
         // No related information
         assert.deepStrictEqual(diagnostic.relatedInformation, []);
@@ -115,7 +115,7 @@ describe('mapRustDiagnosticToVsCode', () => {
         );
         assert.strictEqual(diagnostic.code, 'E0061');
         assert.strictEqual(diagnostic.source, 'rustc');
-        assert.strictEqual(diagnostic.tags, undefined);
+        assert.deepStrictEqual(diagnostic.tags, []);
 
         // One related information for the original definition
         const relatedInformation = diagnostic.relatedInformation;
@@ -149,7 +149,7 @@ describe('mapRustDiagnosticToVsCode', () => {
             ].join('\n')
         );
         assert.strictEqual(diagnostic.code, 'trivially_copy_pass_by_ref');
-        assert.strictEqual(diagnostic.tags, undefined);
+        assert.deepStrictEqual(diagnostic.tags, []);
 
         // One related information for the lint definition
         const relatedInformation = diagnostic.relatedInformation;
@@ -189,7 +189,7 @@ describe('mapRustDiagnosticToVsCode', () => {
         );
         assert.strictEqual(diagnostic.code, 'E0308');
         assert.strictEqual(diagnostic.source, 'rustc');
-        assert.strictEqual(diagnostic.tags, undefined);
+        assert.deepStrictEqual(diagnostic.tags, []);
 
         // No related information
         assert.deepStrictEqual(diagnostic.relatedInformation, []);
diff --git a/editors/code/src/utils/diagnostics/rust.ts b/editors/code/src/utils/diagnostics/rust.ts
index a66b52313e..cd02ee46c9 100644
--- a/editors/code/src/utils/diagnostics/rust.ts
+++ b/editors/code/src/utils/diagnostics/rust.ts
@@ -213,6 +213,7 @@ export function mapRustDiagnosticToVsCode(
     vd.source = source;
     vd.code = code;
     vd.relatedInformation = [];
+    vd.tags = [];
 
     for (const secondarySpan of secondarySpans) {
         const related = mapSecondarySpanToRelated(secondarySpan);
@@ -246,8 +247,6 @@ export function mapRustDiagnosticToVsCode(
         vd.message += `\n${primarySpanLabel}`;
     }
 
-    vd.tags = []
-
     if (isUnusedOrUnnecessary(rd)) {
         vd.tags.push(vscode.DiagnosticTag.Unnecessary);
     }