diff --git a/src/csv-loader/loader.ts b/src/csv-loader/loader.ts
index 259d28a..789148c 100644
--- a/src/csv-loader/loader.ts
+++ b/src/csv-loader/loader.ts
@@ -209,11 +209,21 @@ export function parseCsv(
       // Check if schema string matches a declared type name
       let schema: Schema;
       let declaredTypeName: string | undefined;
+      let columnSchemaString: string | undefined;
       if (declaredTypes.has(schemaString)) {
         schema = declaredTypes.get(schemaString)!;
         declaredTypeName = schemaString;
       } else {
-        schema = parseSchema(schemaString);
+        // Expand any custom type name references before parsing
+        const expandedSchema = expandSchemaString(
+          schemaString,
+          declaredSchemaStrings,
+        );
+        schema = parseSchema(expandedSchema.trim());
+        // Only preserve the original schema string if expansion actually changed it
+        if (expandedSchema !== schemaString) {
+          columnSchemaString = schemaString;
+        }
       }
 
       const config: PropertyConfig = {
@@ -222,6 +232,7 @@ export function parseCsv(
         validator: createValidator(schema),
         parser: (valueString: string) => parseValue(schema, valueString),
         declaredTypeName,
+        schemaString: columnSchemaString,
       };
 
       if (schema.type === "reference") {
diff --git a/src/csv-loader/tests/parseCsv-typeDeclarations.test.ts b/src/csv-loader/tests/parseCsv-typeDeclarations.test.ts
index f489b3b..ed5eecd 100644
--- a/src/csv-loader/tests/parseCsv-typeDeclarations.test.ts
+++ b/src/csv-loader/tests/parseCsv-typeDeclarations.test.ts
@@ -254,6 +254,38 @@ describe("parseCsv - type declarations", () => {
     // Column should reference IntentEffects, not inline expansion
     expect(result.typeDefinition).toContain("readonly effects: IntentEffects;");
   });
+
+  it("should handle custom type inside a tuple used as an array element", () => {
+    const csv = [
+      '# type Type = "apple" | "orange"',
+      "id,items",
+      "string,[Type; int][]",
+      "001,[apple;2];[orange;3]",
+    ].join("\n");
+
+    const result = parseCsv(csv, { emitTypes: false });
+
+    expect(result.data).toHaveLength(1);
+    expect(result.data[0]).toEqual({
+      id: "001",
+      items: [
+        ["apple", 2],
+        ["orange", 3],
+      ],
+    });
+
+    const typeResult = parseCsv(csv, {
+      emitTypes: true,
+      resourceName: "item",
+      currentFilePath: path.join(fixturesDir, "item.csv"),
+    });
+
+    expect(typeResult.typeDefinition).toContain("export type Type =");
+    expect(typeResult.typeDefinition).toContain("[Type; int][]");
+    expect(typeResult.typeDefinition).toContain(
+      "readonly items: [Type; int][];",
+    );
+  });
 });
 
 describe("parseCsv - type declarations with resolveReferences: false", () => {
diff --git a/src/csv-loader/type-gen.ts b/src/csv-loader/type-gen.ts
index da3389c..91be4b0 100644
--- a/src/csv-loader/type-gen.ts
+++ b/src/csv-loader/type-gen.ts
@@ -60,7 +60,8 @@ export function generateTypeDefinition(
     .map((config) => {
       const typeStr = config.declaredTypeName
         ? config.declaredTypeName
-        : schemaToTypeString(config.schema, resourceNames);
+        : (config.schemaString ??
+          schemaToTypeString(config.schema, resourceNames));
       return `    readonly ${config.name}: ${typeStr};`;
     })
     .join("\n");
diff --git a/src/csv-loader/types.ts b/src/csv-loader/types.ts
index 34f75a1..41b7334 100644
--- a/src/csv-loader/types.ts
+++ b/src/csv-loader/types.ts
@@ -78,6 +78,8 @@ export interface PropertyConfig {
   reverseReferenceForeignKey?: string;
   /** When a column uses a declared type name, this stores that name */
   declaredTypeName?: string;
+  /** The original schema string for the column (preserves type name references for output) */
+  schemaString?: string;
 }
 
 /** Parsed reverse reference declaration from a comment line */