diff --git a/auth/utils.py b/auth/utils.py
index 4bded89..9615d69 100644
--- a/auth/utils.py
+++ b/auth/utils.py
@@ -34,9 +34,17 @@ def verify_password(password: str, hash_: str) -> bool:
 class JWTUtils:
     """JWT token utilities"""
     
+    @staticmethod
+    def _get_secret_key() -> str:
+        secret = os.getenv('JWT_SECRET_KEY')
+        if not secret:
+            raise ValueError("JWT_SECRET_KEY environment variable is not set")
+        return secret
+
     @staticmethod
     def create_tokens(user_id: str, username: str) -> Tuple[str, str]:
         """Create access and refresh tokens"""
+        secret_key = JWTUtils._get_secret_key()
         access_token = jwt.encode(
             {
                 'user_id': user_id,
@@ -44,7 +52,7 @@ def create_tokens(user_id: str, username: str) -> Tuple[str, str]:
                 'exp': datetime.utcnow() + timedelta(hours=1),
                 'type': 'access'
             },
-            os.getenv('JWT_SECRET_KEY', 'jwt-secret'),
+            secret_key,
             algorithm='HS256'
         )
         
@@ -55,7 +63,7 @@ def create_tokens(user_id: str, username: str) -> Tuple[str, str]:
                 'exp': datetime.utcnow() + timedelta(days=30),
                 'type': 'refresh'
             },
-            os.getenv('JWT_SECRET_KEY', 'jwt-secret'),
+            secret_key,
             algorithm='HS256'
         )
         
@@ -65,9 +73,10 @@ def create_tokens(user_id: str, username: str) -> Tuple[str, str]:
     def decode_token(token: str) -> Optional[dict]:
         """Decode and verify token"""
         try:
+            secret_key = JWTUtils._get_secret_key()
             payload = jwt.decode(
                 token,
-                os.getenv('JWT_SECRET_KEY', 'jwt-secret'),
+                secret_key,
                 algorithms=['HS256']
             )
             return payload
diff --git a/tests/test_auth_utils.py b/tests/test_auth_utils.py
new file mode 100644
index 0000000..1112a1f
--- /dev/null
+++ b/tests/test_auth_utils.py
@@ -0,0 +1,44 @@
+import os
+import sys
+from unittest.mock import MagicMock
+
+# Mock external dependency cache_db before auth.utils is imported
+sys.modules['cache_db'] = MagicMock()
+sys.modules['cache_db.redis_client'] = MagicMock()
+sys.modules['cache_db.models'] = MagicMock()
+
+import pytest
+from auth.utils import JWTUtils
+
+
+def test_jwt_utils_requires_secret_key():
+    """Test that JWTUtils raises ValueError when JWT_SECRET_KEY is not set."""
+    os.environ.pop("JWT_SECRET_KEY", None)
+    with pytest.raises(ValueError, match="JWT_SECRET_KEY environment variable is not set"):
+        JWTUtils.create_tokens("user123", "testuser")
+
+    with pytest.raises(ValueError, match="JWT_SECRET_KEY environment variable is not set"):
+        JWTUtils.decode_token("some.jwt.token")
+
+
+def test_jwt_utils_create_and_decode_tokens():
+    """Test creating and decoding JWT tokens when JWT_SECRET_KEY is configured."""
+    os.environ["JWT_SECRET_KEY"] = "super-secret-key-for-testing"
+    try:
+        access_token, refresh_token = JWTUtils.create_tokens("user123", "testuser")
+        assert access_token is not None
+        assert refresh_token is not None
+
+        decoded = JWTUtils.decode_token(access_token)
+        assert decoded is not None
+        assert decoded["user_id"] == "user123"
+        assert decoded["username"] == "testuser"
+        assert decoded["type"] == "access"
+
+        decoded_refresh = JWTUtils.decode_token(refresh_token)
+        assert decoded_refresh is not None
+        assert decoded_refresh["user_id"] == "user123"
+        assert decoded_refresh["username"] == "testuser"
+        assert decoded_refresh["type"] == "refresh"
+    finally:
+        os.environ.pop("JWT_SECRET_KEY", None)