diff --git a/src/agentex/lib/core/temporal/workers/worker.py b/src/agentex/lib/core/temporal/workers/worker.py
index 46e14c0e..4a8fee9e 100644
--- a/src/agentex/lib/core/temporal/workers/worker.py
+++ b/src/agentex/lib/core/temporal/workers/worker.py
@@ -112,7 +112,7 @@ def __init__(
         task_queue,
         max_workers: int = 10,
         max_concurrent_activities: int = 10,
-        health_check_port: int = int(os.environ.get("HEALTH_CHECK_PORT")),
+        health_check_port: int | None = None,
         plugins: list = [],
     ):
         self.task_queue = task_queue
@@ -121,7 +121,7 @@ def __init__(
         self.max_concurrent_activities = max_concurrent_activities
         self.health_check_server_running = False
         self.healthy = False
-        self.health_check_port = health_check_port
+        self.health_check_port = health_check_port if health_check_port is not None else EnvironmentVariables.refresh().HEALTH_CHECK_PORT
         self.plugins = plugins
 
     @overload
diff --git a/tests/lib/test_agentex_worker.py b/tests/lib/test_agentex_worker.py
new file mode 100644
index 00000000..76347f0d
--- /dev/null
+++ b/tests/lib/test_agentex_worker.py
@@ -0,0 +1,90 @@
+import os
+from unittest.mock import patch
+
+import pytest
+
+
+class TestAgentexWorker:
+    """Tests for AgentexWorker initialization and configuration."""
+
+    @pytest.fixture(autouse=True)
+    def cleanup_env(self):
+        """Cleanup environment variables after each test."""
+        yield
+        # Clean up HEALTH_CHECK_PORT if it was set during test
+        os.environ.pop("HEALTH_CHECK_PORT", None)
+
+    def test_worker_init_uses_default_health_check_port(self):
+        """Test that worker uses default health_check_port of 80 when not provided."""
+        from agentex.lib.core.temporal.workers.worker import AgentexWorker
+
+        # Ensure HEALTH_CHECK_PORT is not in environment
+        os.environ.pop("HEALTH_CHECK_PORT", None)
+
+        # Mock EnvironmentVariables.refresh to avoid loading .env files
+        with patch("agentex.lib.core.temporal.workers.worker.EnvironmentVariables") as mock_env_vars:
+            mock_instance = mock_env_vars.refresh.return_value
+            mock_instance.HEALTH_CHECK_PORT = 80
+
+            worker = AgentexWorker(task_queue="test-queue")
+
+            assert worker.health_check_port == 80, "Worker should use default health_check_port of 80"
+
+    def test_worker_init_with_explicit_health_check_port(self):
+        """Test that worker uses explicit health_check_port parameter when provided."""
+        from agentex.lib.core.temporal.workers.worker import AgentexWorker
+
+        worker = AgentexWorker(task_queue="test-queue", health_check_port=8080)
+
+        assert worker.health_check_port == 8080, "Worker should use explicitly provided health_check_port"
+
+    def test_worker_init_explicit_port_overrides_environment(self):
+        """Test that explicit health_check_port parameter overrides environment variable."""
+        from agentex.lib.core.temporal.workers.worker import AgentexWorker
+
+        # Set environment variable
+        os.environ["HEALTH_CHECK_PORT"] = "9000"
+
+        worker = AgentexWorker(task_queue="test-queue", health_check_port=8080)
+
+        assert worker.health_check_port == 8080, "Explicit parameter should override environment variable"
+
+    @pytest.mark.parametrize(
+        "env_port,expected_port",
+        [
+            (None, 80),  # No env var, should use default
+            ("8080", 8080),  # Env var set, should use it
+            ("443", 443),  # Different port
+        ],
+    )
+    def test_worker_init_respects_environment_variable(self, env_port, expected_port):
+        """Test that worker respects HEALTH_CHECK_PORT from EnvironmentVariables."""
+        from agentex.lib.core.temporal.workers.worker import AgentexWorker
+
+        # Mock EnvironmentVariables.refresh to return expected port
+        with patch("agentex.lib.core.temporal.workers.worker.EnvironmentVariables") as mock_env_vars:
+            mock_instance = mock_env_vars.refresh.return_value
+            mock_instance.HEALTH_CHECK_PORT = expected_port
+
+            worker = AgentexWorker(task_queue="test-queue")
+
+            assert worker.health_check_port == expected_port, f"Worker should use health_check_port {expected_port}"
+
+    def test_worker_init_basic_attributes(self):
+        """Test that worker initializes with correct basic attributes."""
+        from agentex.lib.core.temporal.workers.worker import AgentexWorker
+
+        worker = AgentexWorker(
+            task_queue="test-queue",
+            max_workers=20,
+            max_concurrent_activities=15,
+            health_check_port=8080,
+        )
+
+        assert worker.task_queue == "test-queue"
+        assert worker.max_workers == 20
+        assert worker.max_concurrent_activities == 15
+        assert worker.health_check_port == 8080
+        assert worker.health_check_server_running is False
+        assert worker.healthy is False
+        assert worker.plugins == []