diff --git a/lib/base/connection.js b/lib/base/connection.js
index 70cec19c97..572e3c2225 100644
--- a/lib/base/connection.js
+++ b/lib/base/connection.js
@@ -37,6 +37,7 @@ class BaseConnection extends EventEmitter {
   constructor(opts) {
     super();
     this.config = opts.config;
+    this.state = 'disconnected';
     // TODO: fill defaults
     // if no params, connect to /var/lib/mysql/mysql.sock ( /tmp/mysql.sock on OSX )
     // if host is given, connect to host:3306
@@ -134,10 +135,12 @@ class BaseConnection extends EventEmitter {
         }
         this._handshakePacket = handshakeCommand.handshake;
         this.threadId = handshakeCommand.handshake.connectionId;
+        this.state = "connected";
         this.emit('connect', handshakeCommand.handshake);
       });
       handshakeCommand.on('error', (err) => {
         this._closing = true;
+        this.state = "disconnected";
         this._notifyError(err);
       });
       this.addCommand(handshakeCommand);
@@ -207,6 +210,7 @@ class BaseConnection extends EventEmitter {
   // notify all commands in the queue and bubble error as connection "error"
   // called on stream error or unexpected termination
   _notifyError(err) {
+    this.state = "protocol_error";
     if (this.connectTimeout) {
       Timers.clearTimeout(this.connectTimeout);
       this.connectTimeout = null;
@@ -358,8 +362,8 @@ class BaseConnection extends EventEmitter {
         checkServerIdentity: verifyIdentity
           ? Tls.checkServerIdentity
           : function () {
-              return undefined;
-            },
+            return undefined;
+          },
         secureContext,
         isServer: false,
         socket: this.stream,
@@ -409,6 +413,7 @@ class BaseConnection extends EventEmitter {
     const err = new Error(message);
     err.fatal = true;
     err.code = code || 'PROTOCOL_ERROR';
+    this.state = "protocol_error";
     this.emit('error', err);
   }
 
@@ -769,6 +774,7 @@ class BaseConnection extends EventEmitter {
       this.connectTimeout = null;
     }
     this._closing = true;
+    this.state = 'disconnected';
     this.stream.end();
     this.addCommand = this._addCommandClosedState;
   }
@@ -893,6 +899,7 @@ class BaseConnection extends EventEmitter {
 
   // ===============================================================
   end(callback) {
+    this.state = 'disconnected';
     if (this.config.isServer) {
       this._closing = true;
       const quitCmd = new EventEmitter();
diff --git a/test/unit/connection/test-connection-state.test.cjs b/test/unit/connection/test-connection-state.test.cjs
new file mode 100644
index 0000000000..0533871667
--- /dev/null
+++ b/test/unit/connection/test-connection-state.test.cjs
@@ -0,0 +1,98 @@
+'use strict';
+const { assert, describe, it, beforeEach, afterEach } = require('poku');
+const common = require('../../common.test.cjs');
+
+(async () => {
+  await describe('Connection state', async () => {
+    let connection;
+
+    beforeEach(() => (connection = common.createConnection().promise()));
+
+    afterEach(async () => {
+      if (!connection) return;
+      try {
+        await connection.end();
+      } catch (e) {
+        // ignore teardown errors
+      }
+    });
+
+    await it('connects and sets state to connected', async () => {
+      await connection?.connect();
+      assert.equal(connection.connection.state, 'connected');
+    });
+
+    await it('connects and disconnect: sets state to connected and disconnected close() is called.', async () => {
+      await connection?.connect();
+      assert.equal(connection.connection.state, 'connected');
+      await connection.close();
+      assert.equal(connection.connection.state, 'disconnected');
+    });
+
+    await it('connects and disconnect: sets state to connected and disconnected when end() is called.', async () => {
+      await connection?.connect();
+      assert.equal(connection.connection.state, 'connected');
+      await connection.end();
+      assert.equal(connection.connection.state, 'disconnected');
+    });
+
+    await it('state is protocol_error if creds are wrong.', async () => {
+      const badConnection = common.createConnection({ password: "WR0NG", user: 'wrong' }).promise();
+      try {
+        await badConnection.connect();
+        assert.fail('expected connect() to throw for bad credentials');
+      } catch (err) {
+        assert.equal(badConnection.connection.state, 'protocol_error');
+      } finally {
+        try {
+          await bad.end();
+        } catch (e) { }
+      }
+    });
+
+    await it('ping keeps connection operational', async () => {
+      await connection?.connect();
+      await connection.ping();
+      assert.equal(connection.connection.state, 'connected');
+    });
+
+    await it('simple query keeps state operational and returns rows', async () => {
+      await connection?.connect();
+      const [rows] = await connection.query('SELECT 1 AS x');
+      assert.equal(rows[0].x, 1);
+      assert.equal(connection.connection.state, 'connected');
+    });
+
+    await it('socket destroy produces disconnected', async () => {
+      await connection?.connect();
+      const raw = connection.connection;
+      // attach error listener early to avoid uncaught exceptions
+      let sawError = null;
+      raw.once('error', (e) => { sawError = e; });
+      // Force a network-style drop
+      raw.stream.destroy(new Error('simulate network drop'));
+      // wait a bit for event propagation
+      await new Promise((r) => setTimeout(r, 50));
+      assert.ok(sawError instanceof Error, 'expected an error emitted');
+      assert.equal(connection.connection.state, 'disconnected');
+    });
+
+    await it('changeUser to invalid account yields disconnected', async () => {
+      await connection?.connect();
+      const raw = connection.connection;
+      // use changeUser to induce auth error (assuming user 'nope' doesn't exist)
+      let gotErr = null;
+      assert.equal(raw.state, "connected");
+      raw.on('error', (e) => { gotErr = e; });
+      try {
+        await connection.changeUser({ user: 'nope', password: 'bad' });
+      } catch (err) {
+        gotErr = err;
+      }
+      // allow propagation
+      await new Promise((r) => setTimeout(r, 20));
+      assert.ok(gotErr instanceof Error, 'expected changeUser to emit error');
+      assert.equal(raw.state, 'disconnected');
+    });
+  });
+})();