diff --git a/src/test/java/org/casbin/jcasbin/main/InOperatorBugTest.java b/src/test/java/org/casbin/jcasbin/main/InOperatorBugTest.java
new file mode 100644
index 00000000..04742a83
--- /dev/null
+++ b/src/test/java/org/casbin/jcasbin/main/InOperatorBugTest.java
@@ -0,0 +1,87 @@
+package org.casbin.jcasbin.main;
+
+import org.testng.annotations.Test;
+import java.io.File;
+import java.io.FileWriter;
+import static org.testng.Assert.*;
+
+/**
+ * Test for the 'in' operator bug with tuple literals
+ * Issue: 'in' of matcher doesn't work: "m = g(r.sub, p.sub) && r.obj == p.obj && r.act == p.act || r.obj in ('data2', 'data3')"
+ */
+public class InOperatorBugTest {
+    
+    @Test
+    public void testInOperatorWithTupleLiterals() throws Exception {
+        File modelFile = null;
+        File policyFile = null;
+        
+        try {
+            // Create temporary model and policy files
+            modelFile = File.createTempFile("test_in_op_model", ".conf");
+            policyFile = File.createTempFile("test_in_op_policy", ".csv");
+            
+            // Write model with matcher containing "in" operator with tuple literals
+            String modelText = "[request_definition]\n" +
+                               "r = sub, obj, act\n" +
+                               "\n" +
+                               "[policy_definition]\n" +
+                               "p = sub, obj, act\n" +
+                               "\n" +
+                               "[role_definition]\n" +
+                               "g = _, _\n" +
+                               "\n" +
+                               "[policy_effect]\n" +
+                               "e = some(where (p.eft == allow))\n" +
+                               "\n" +
+                               "[matchers]\n" +
+                               "m = g(r.sub, p.sub) && r.obj == p.obj && r.act == p.act || r.obj in ('data2', 'data3')\n";
+            
+            try (FileWriter writer = new FileWriter(modelFile)) {
+                writer.write(modelText);
+            }
+            
+            // Write policy
+            String policyText = "p, reader, data1, read\n" +
+                                "p, writer, data1, write\n" +
+                                "\n" +
+                                "g, alice, reader\n";
+            
+            try (FileWriter writer = new FileWriter(policyFile)) {
+                writer.write(policyText);
+            }
+            
+            // Create enforcer
+            Enforcer e = new Enforcer(modelFile.getAbsolutePath(), policyFile.getAbsolutePath());
+            
+            // Test 1: Should allow access because alice is a reader and wants to read data1
+            assertTrue(e.enforce("alice", "data1", "read"));
+            
+            // Test 2: Should allow access because data2 is in the tuple ('data2', 'data3')
+            // even though alice doesn't have explicit permission for data2
+            assertTrue(e.enforce("alice", "data2", "read"));
+            
+            // Test 3: Should allow access because data3 is in the tuple ('data2', 'data3')
+            // The tuple check bypasses the role-based access control
+            assertTrue(e.enforce("alice", "data3", "write"));
+            
+            // Test 4: Should deny access because data4 is not in the tuple and alice is not a writer
+            assertFalse(e.enforce("alice", "data4", "write"));
+            
+            // Test 5: Even a user without any role can access data2/data3 due to tuple matching
+            assertTrue(e.enforce("bob", "data2", "read"));
+            assertTrue(e.enforce("bob", "data3", "write"));
+            
+            // Test 6: User without role cannot access data outside the tuple
+            assertFalse(e.enforce("bob", "data4", "write"));
+        } finally {
+            // Clean up temporary files
+            if (modelFile != null && modelFile.exists()) {
+                modelFile.delete();
+            }
+            if (policyFile != null && policyFile.exists()) {
+                policyFile.delete();
+            }
+        }
+    }
+}