diff --git a/test/conftest.py b/test/conftest.py
index 61d42ca..f4a58ef 100644
--- a/test/conftest.py
+++ b/test/conftest.py
@@ -5,32 +5,32 @@ from escpos.printer import LP, CupsPrinter, Dummy, File, Network, Serial, Usb, W
 
 
 @pytest.fixture
-def driver():
+def driver() -> Dummy:
     return Dummy()
 
 
 @pytest.fixture
-def usbprinter():
+def usbprinter() -> Usb:
     return Usb()
 
 
 @pytest.fixture
-def serialprinter():
+def serialprinter() -> Serial:
     return Serial()
 
 
 @pytest.fixture
-def networkprinter():
+def networkprinter() -> Network:
     return Network()
 
 
 @pytest.fixture
-def fileprinter():
+def fileprinter() -> File:
     return File()
 
 
 @pytest.fixture
-def lpprinter():
+def lpprinter() -> LP:
     return LP()
 
 
diff --git a/test/test_functions/test_function_text.py b/test/test_functions/test_function_text.py
index 7a72f34..3169dd5 100644
--- a/test/test_functions/test_function_text.py
+++ b/test/test_functions/test_function_text.py
@@ -15,7 +15,7 @@ from hypothesis import given
 from escpos.printer import Dummy
 
 
-def get_printer():
+def get_printer() -> Dummy:
     return Dummy(magic_encode_args={"disabled": True, "encoding": "CP437"})