diff --git a/aoclib/day.py b/aoclib/day.py
index 00cabef..f44e0c7 100644
--- a/aoclib/day.py
+++ b/aoclib/day.py
@@ -1,5 +1,5 @@
 import os
-from typing import List, Any
+from typing import List, Any, Type
 from .tools import splitLine
 from .output import printSolution
 
@@ -13,7 +13,7 @@ class AOCDay:
     test_solutions_p1: List
     test_solutions_p2: List
 
-    def __init__(self, day):
+    def __init__(self, day: int):
         self.day = day
         with open(os.path.join(INPUTS_PATH, "input%02d" % day)) as f:
             self.input = f.read().splitlines()
@@ -52,13 +52,13 @@ class AOCDay:
         self.input = live_input
         return True
 
-    def getInputListAsType(self, return_type):
+    def getInputListAsType(self, return_type: Type) -> List:
         """
         get input as list casted to return_type, each line representing one list entry
         """
         return [return_type(i) for i in self.input]
 
-    def getMultiLineInputAsArray(self, return_type=None, join_char=None):
+    def getMultiLineInputAsArray(self, return_type: Type = None, join_char: str = None) -> List:
         """
         get input for day x as 2d array, split by empty lines
         """
@@ -83,7 +83,7 @@ class AOCDay:
 
         return return_array
 
-    def getInputAs2DArray(self, return_type=None):
+    def getInputAs2DArray(self, return_type: Type = None) -> List:
         """
         get input for day x as 2d-array (a[line][pos])
         """
@@ -96,7 +96,7 @@ class AOCDay:
 
             return return_array
 
-    def getInputAsArraySplit(self, split_char=',', return_type=None):
+    def getInputAsArraySplit(self, split_char: str = ',', return_type: Type = None) -> List:
         """
         get input for day x with the lines split by split_char
         if input has only one line, returns a 1d array with the values