diff --git a/src/rules/convertRules.test.ts b/src/rules/convertRules.test.ts
index 20aa66b90..8ac1ae890 100644
--- a/src/rules/convertRules.test.ts
+++ b/src/rules/convertRules.test.ts
@@ -183,6 +183,96 @@ describe("convertRules", () => {
         );
     });
 
+    it("merges and deduplicates rule notices", () => {
+        // Arrange
+        const tslintRule: TSLintRuleOptions = {
+            ruleArguments: [],
+            ruleName: "tslint-rule-a",
+            ruleSeverity: "error",
+        };
+        const conversionResult = {
+            rules: [
+                {
+                    ruleName: "eslint-rule-a",
+                    notices: ["notice-1", "notice-2"],
+                },
+                {
+                    ruleName: "eslint-rule-a",
+                    notices: ["notice-1"],
+                },
+            ],
+        };
+        const mergedArguments = [{ merged: true }];
+        const converters = new Map([[tslintRule.ruleName, () => conversionResult]]);
+        const mergers = new Map([[conversionResult.rules[0].ruleName, () => mergedArguments]]);
+
+        // Act
+        const { converted } = convertRules(
+            { converters, mergers },
+            { [tslintRule.ruleName]: tslintRule },
+        );
+
+        // Assert
+        expect(converted).toEqual(
+            new Map([
+                [
+                    "eslint-rule-a",
+                    {
+                        ruleArguments: mergedArguments,
+                        ruleName: "eslint-rule-a",
+                        ruleSeverity: "error",
+                        notices: ["notice-1", "notice-2"],
+                    },
+                ],
+            ]),
+        );
+    });
+
+    it("merges undefined notices", () => {
+        // Arrange
+        const tslintRule: TSLintRuleOptions = {
+            ruleArguments: [],
+            ruleName: "tslint-rule-a",
+            ruleSeverity: "error",
+        };
+        const conversionResult = {
+            rules: [
+                {
+                    ruleName: "eslint-rule-a",
+                    notices: undefined,
+                },
+                {
+                    ruleName: "eslint-rule-a",
+                    notices: undefined,
+                },
+            ],
+        };
+        const mergedArguments = [{ merged: true }];
+        const converters = new Map([[tslintRule.ruleName, () => conversionResult]]);
+        const mergers = new Map([[conversionResult.rules[0].ruleName, () => mergedArguments]]);
+
+        // Act
+        const { converted } = convertRules(
+            { converters, mergers },
+            { [tslintRule.ruleName]: tslintRule },
+        );
+
+        // Assert
+        expect(converted).toEqual(
+            new Map([
+                [
+                    "eslint-rule-a",
+                    {
+                        ruleArguments: mergedArguments,
+                        ruleName: "eslint-rule-a",
+                        ruleSeverity: "error",
+                        notices: [],
+                    },
+                ],
+            ]),
+        );
+    });
+
     it("marks a new plugin when a conversion has a new plugin", () => {
         // Arrange
         const tslintRule: TSLintRuleOptions = {
diff --git a/src/rules/convertRules.ts b/src/rules/convertRules.ts
index 8090c5a11..d28c42199 100644
--- a/src/rules/convertRules.ts
+++ b/src/rules/convertRules.ts
@@ -78,7 +78,7 @@ export const convertRules = (
                         existingConversion.ruleArguments,
                         newConversion.ruleArguments,
                     ),
-                    notices: [...existingNotices, ...newNotices],
+                    notices: Array.from(new Set([...existingNotices, ...newNotices])),
                 });
             }
         }