diff --git a/package.json b/package.json
index 1b23f52..af08a45 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@samchon/openapi",
-  "version": "1.2.0",
+  "version": "1.2.1",
   "description": "OpenAPI definitions and converters for 'typia' and 'nestia'.",
   "main": "./lib/index.js",
   "module": "./lib/index.mjs",
diff --git a/src/converters/OpenApiV3Downgrader.ts b/src/converters/OpenApiV3Downgrader.ts
index fdb8697..3991901 100644
--- a/src/converters/OpenApiV3Downgrader.ts
+++ b/src/converters/OpenApiV3Downgrader.ts
@@ -208,31 +208,29 @@ export namespace OpenApiV3Downgrader {
             items: downgradeSchema(collection)(schema.items),
           });
         else if (OpenApiTypeChecker.isTuple(schema))
-          union.push({
+          visit({
             ...schema,
-            items: ((): OpenApiV3.IJsonSchema => {
-              if (schema.additionalItems === true) return {};
-              const elements = [
+            type: "array",
+            items: {
+              oneOf: [
                 ...schema.prefixItems,
-                ...(typeof schema.additionalItems === "object"
-                  ? [downgradeSchema(collection)(schema.additionalItems)]
+                ...(typeof schema.additionalItems === "object" &&
+                schema.additionalItems !== null
+                  ? [schema.additionalItems]
                   : []),
-              ];
-              if (elements.length === 0) return {};
-              return {
-                oneOf: elements.map(downgradeSchema(collection) as any),
-              };
-            })(),
-            minItems: schema.prefixItems.length,
+              ],
+            },
+            minItems: schema.minItems ?? schema.prefixItems.length,
             maxItems:
-              !!schema.additionalItems === true
+              schema.maxItems ??
+              (schema.additionalItems === true
                 ? undefined
-                : schema.prefixItems.length,
+                : schema.prefixItems.length),
             ...{
               prefixItems: undefined,
               additionalItems: undefined,
             },
-          });
+          } satisfies OpenApi.IJsonSchema.IArray);
         else if (OpenApiTypeChecker.isObject(schema))
           union.push({
             ...schema,
diff --git a/src/converters/SwaggerV2Downgrader.ts b/src/converters/SwaggerV2Downgrader.ts
index 2dd08b5..ee4a380 100644
--- a/src/converters/SwaggerV2Downgrader.ts
+++ b/src/converters/SwaggerV2Downgrader.ts
@@ -228,34 +228,29 @@ export namespace SwaggerV2Downgrader {
               : undefined,
           });
         else if (OpenApiTypeChecker.isTuple(schema))
-          union.push({
+          visit({
             ...schema,
-            items: ((): SwaggerV2.IJsonSchema => {
-              if (schema.additionalItems === true) return {};
-              const elements = [
+            type: "array",
+            items: {
+              oneOf: [
                 ...schema.prefixItems,
-                ...(typeof schema.additionalItems === "object"
-                  ? [downgradeSchema(collection)(schema.additionalItems)]
+                ...(typeof schema.additionalItems === "object" &&
+                schema.additionalItems !== null
+                  ? [schema.additionalItems]
                   : []),
-              ];
-              if (elements.length === 0) return {};
-              return {
-                "x-oneOf": elements.map(downgradeSchema(collection) as any),
-              };
-            })(),
-            minItems: schema.prefixItems.length,
+              ],
+            },
+            minItems: schema.minItems ?? schema.prefixItems.length,
             maxItems:
-              !!schema.additionalItems === true
+              schema.maxItems ??
+              (schema.additionalItems === true
                 ? undefined
-                : schema.prefixItems.length,
+                : schema.prefixItems.length),
             ...{
               prefixItems: undefined,
               additionalItems: undefined,
             },
-            examples: schema.examples
-              ? Object.values(schema.examples)
-              : undefined,
-          });
+          } satisfies OpenApi.IJsonSchema.IArray);
         else if (OpenApiTypeChecker.isObject(schema))
           union.push({
             ...schema,
@@ -285,16 +280,18 @@ export namespace SwaggerV2Downgrader {
         const insert = (value: any): void => {
           const matched: SwaggerV2.IJsonSchema.INumber | undefined = union.find(
             (u) =>
-              (u as SwaggerV2.IJsonSchema.__ISignificant<any>).type === value,
+              (u as SwaggerV2.IJsonSchema.__ISignificant<any>).type ===
+              typeof value,
           ) as SwaggerV2.IJsonSchema.INumber | undefined;
           if (matched !== undefined) {
             matched.enum ??= [];
             matched.enum.push(value);
           } else union.push({ type: typeof value as "number", enum: [value] });
-          if (OpenApiTypeChecker.isConstant(schema)) insert(schema.const);
-          else if (OpenApiTypeChecker.isOneOf(schema))
-            schema.oneOf.forEach(insert);
         };
+        if (OpenApiTypeChecker.isConstant(schema)) insert(schema.const);
+        else if (OpenApiTypeChecker.isOneOf(schema))
+          for (const u of schema.oneOf)
+            if (OpenApiTypeChecker.isConstant(u)) insert(u.const);
       };
 
       visit(input);
diff --git a/test/features/openapi/test_json_schema_downgrade_v20_tuple.ts b/test/features/openapi/test_json_schema_downgrade_v20_tuple.ts
new file mode 100644
index 0000000..6d945ba
--- /dev/null
+++ b/test/features/openapi/test_json_schema_downgrade_v20_tuple.ts
@@ -0,0 +1,35 @@
+import { TestValidator } from "@nestia/e2e";
+import { SwaggerV2Downgrader } from "@samchon/openapi/lib/converters/SwaggerV2Downgrader";
+import typia from "typia";
+
+export const test_json_schema_downgrade_v20_tuple = (): void => {
+  const collection = typia.json.application<[[false, 1, 2, "three", null]]>();
+  const schema = SwaggerV2Downgrader.downgradeSchema({
+    original: collection.components,
+    downgraded: {},
+  })(collection.schemas[0]);
+  TestValidator.equals("tuple")(schema)({
+    type: "array",
+    items: {
+      "x-oneOf": [
+        {
+          type: "boolean",
+          enum: [false],
+          "x-nullable": true,
+        },
+        {
+          type: "number",
+          enum: [1, 2],
+          "x-nullable": true,
+        },
+        {
+          type: "string",
+          enum: ["three"],
+          "x-nullable": true,
+        },
+      ],
+    },
+    minItems: 5,
+    maxItems: 5,
+  });
+};
diff --git a/test/features/openapi/test_json_schema_downgrade_v30_tuple.ts b/test/features/openapi/test_json_schema_downgrade_v30_tuple.ts
new file mode 100644
index 0000000..fc0bff9
--- /dev/null
+++ b/test/features/openapi/test_json_schema_downgrade_v30_tuple.ts
@@ -0,0 +1,35 @@
+import { TestValidator } from "@nestia/e2e";
+import { OpenApiV3Downgrader } from "@samchon/openapi/lib/converters/OpenApiV3Downgrader";
+import typia from "typia";
+
+export const test_json_schema_downgrade_v30_tuple = (): void => {
+  const collection = typia.json.application<[[false, 1, 2, "three", null]]>();
+  const schema = OpenApiV3Downgrader.downgradeSchema({
+    original: collection.components,
+    downgraded: {},
+  })(collection.schemas[0]);
+  TestValidator.equals("tuple")(schema)({
+    type: "array",
+    items: {
+      oneOf: [
+        {
+          type: "boolean",
+          enum: [false],
+          nullable: true,
+        },
+        {
+          type: "number",
+          enum: [1, 2],
+          nullable: true,
+        },
+        {
+          type: "string",
+          enum: ["three"],
+          nullable: true,
+        },
+      ],
+    },
+    minItems: 5,
+    maxItems: 5,
+  });
+};