diff --git a/hashes/adler32.py b/hashes/adler32.py
index fad747abe3c3..13d0b2bb7a3c 100644
--- a/hashes/adler32.py
+++ b/hashes/adler32.py
@@ -9,7 +9,7 @@
 """
 
 
-def adler32(plain_text: str) -> str:
+def adler32(plain_text: str) -> int:
     """
     Function implements adler-32 hash.
     Itterates and evaluates new value for each character
diff --git a/hashes/chaos_machine.py b/hashes/chaos_machine.py
index 1bdf984b68de..ec0c78fc88f2 100644
--- a/hashes/chaos_machine.py
+++ b/hashes/chaos_machine.py
@@ -6,7 +6,8 @@
 m = 5
 
 # Buffer Space (with Parameters Space)
-buffer_space, params_space = [], []
+buffer_space: list[int] = []
+params_space: list[int] = []
 
 # Machine Time
 machine_time = 0
diff --git a/hashes/md5.py b/hashes/md5.py
index b7888fb610ac..e69f08770f7f 100644
--- a/hashes/md5.py
+++ b/hashes/md5.py
@@ -25,7 +25,7 @@ def rearrange(bitString32):
     return newString
 
 
-def reformatHex(i):
+def reformatHex(i: int) -> str:
     """[summary]
     Converts the given integer into 8-digit hex number.
 
@@ -81,7 +81,7 @@ def getBlock(bitString):
         currPos += 512
 
 
-def not32(i):
+def not32(i: int) -> int:
     """
     >>> not32(34)
     4294967261
diff --git a/hashes/sdbm.py b/hashes/sdbm.py
index 86d47a1d9967..daf292717f75 100644
--- a/hashes/sdbm.py
+++ b/hashes/sdbm.py
@@ -19,7 +19,7 @@
 """
 
 
-def sdbm(plain_text: str) -> str:
+def sdbm(plain_text: str) -> int:
     """
     Function implements sdbm hash, easy to use, great for bits scrambling.
     iterates over each character in the given string and applies function to each of
diff --git a/traversals/binary_tree_traversals.py b/traversals/binary_tree_traversals.py
index cb471ba55bac..f919a2962354 100644
--- a/traversals/binary_tree_traversals.py
+++ b/traversals/binary_tree_traversals.py
@@ -188,7 +188,7 @@ def pre_order_iter(node: TreeNode) -> None:
     """
     if not isinstance(node, TreeNode) or not node:
         return
-    stack: List[TreeNode] = []
+    stack: list[TreeNode] = []
     n = node
     while n or stack:
         while n:  # start from root node, find its left child
@@ -218,7 +218,7 @@ def in_order_iter(node: TreeNode) -> None:
     """
     if not isinstance(node, TreeNode) or not node:
         return
-    stack: List[TreeNode] = []
+    stack: list[TreeNode] = []
     n = node
     while n or stack:
         while n: