diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..78aec93
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,15 @@
+"""
+Pytest configuration file with global mocks for external dependencies.
+
+This module mocks the 'sientia' module to avoid requiring its installation
+during unit tests. The mock is registered in sys.modules before any test
+imports are executed.
+"""
+import sys
+from unittest.mock import MagicMock
+
+# Mock sientia module
+sientia_mock = MagicMock()
+sientia_mock.ModelAnalysis = MagicMock
+sys.modules['sientia'] = sientia_mock
+sys.modules['sientia.ModelAnalysis'] = MagicMock()