diff --git a/libs/java-ast/src/lib/core/Writer.spec.ts b/libs/java-ast/src/lib/core/Writer.spec.ts
index 3043cd7..af87e0c 100644
--- a/libs/java-ast/src/lib/core/Writer.spec.ts
+++ b/libs/java-ast/src/lib/core/Writer.spec.ts
@@ -152,4 +152,20 @@ describe("Writer", () => {
     const formatted = writer.formatCode("public   void   method()   {");
     expect(formatted).toBe("public void method() {");
   });
+
+  it("should correctly de-duplicate imports and references", () => {
+    writer.addReference(
+      new ClassReference({ name: "ArrayList", packageName: "java.util" }),
+    );
+    writer.addReference(
+      new ClassReference({ name: "ArrayList", packageName: "java.util" }),
+    );
+    writer.addImport("java.util.ArrayList");
+    writer.addImport("java.util.ArrayList");
+
+    const output = writer.toString();
+    expect(output.trim()).toBe(`package com.example;
+
+import java.util.ArrayList;`);
+  });
 });
diff --git a/libs/java-ast/src/lib/core/Writer.ts b/libs/java-ast/src/lib/core/Writer.ts
index 1eb7716..0155564 100644
--- a/libs/java-ast/src/lib/core/Writer.ts
+++ b/libs/java-ast/src/lib/core/Writer.ts
@@ -26,7 +26,7 @@ export class Writer implements IWriter {
   private indentLevel = 0;
   private buffer = "";
   private imports: Set<string> = new Set();
-  private references: Set<ClassReference> = new Set();
+  private references: Set<string> = new Set();
   private packageName: string;
   private skipPackageDeclaration: boolean;
 
@@ -111,7 +111,9 @@ export class Writer implements IWriter {
     if (reference.packageName === this.packageName) {
       return;
     }
-    this.references.add(reference);
+    // Sets compare objects by reference, so we need to
+    // convert to string before adding
+    this.references.add(`${reference.packageName}.${reference.name}`);
   }
 
   /**
@@ -155,11 +157,10 @@ export class Writer implements IWriter {
       result += `package ${this.packageName};\n\n`;
     }
 
-    // Write imports
-    const allImports = [...this.imports];
-    this.references.forEach((ref) => {
-      allImports.push(`${ref.packageName}.${ref.name}`);
-    });
+    // Combine imports with references, and remove duplicates
+    const allImports = [
+      ...new Set<string>([...this.imports, ...this.references]),
+    ];
 
     // Sort imports
     allImports.sort().forEach((importName) => {
diff --git a/libs/java-ast/tests/__snapshots__/ComplexExample.spec.ts.snap b/libs/java-ast/tests/__snapshots__/ComplexExample.spec.ts.snap
index 8ded061..cc76c1e 100644
--- a/libs/java-ast/tests/__snapshots__/ComplexExample.spec.ts.snap
+++ b/libs/java-ast/tests/__snapshots__/ComplexExample.spec.ts.snap
@@ -3,37 +3,23 @@
 exports[`Complex Example should generate a complex Spring Boot controller 1`] = `
 "package com.example.controller;
 
-import com.example.dto.UserDTO;
-import com.example.dto.UserDTO;
-import com.example.dto.UserDTO;
-import com.example.dto.UserDTO;
-import com.example.dto.UserDTO;
-import com.example.dto.UserDTO;
 import com.example.dto.UserDTO;
 import com.example.exception.DuplicateResourceException;
 import com.example.service.UserService;
-import com.example.service.UserService;
 import io.swagger.v3.oas.annotations.Operation;
 import java.lang.String;
 import java.net.URI;
 import java.util.HashMap;
 import java.util.List;
-import java.util.List;
-import java.util.Map;
 import java.util.Map;
 import javax.validation.Valid;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.beans.factory.Autowired;
 import org.springframework.http.HttpStatus;
-import org.springframework.http.HttpStatus;
-import org.springframework.http.HttpStatus;
-import org.springframework.http.ResponseEntity;
-import org.springframework.http.ResponseEntity;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.MethodArgumentNotValidException.MethodArgumentNotValidException;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestBody;