diff --git a/aioping/__init__.py b/aioping/__init__.py
index 9221d91..070809b 100644
--- a/aioping/__init__.py
+++ b/aioping/__init__.py
@@ -88,6 +88,7 @@
 import random
 import platform
 import os
+from typing import Optional, Tuple, Union
 
 logger = logging.getLogger("aioping")
 default_timer = time.perf_counter
@@ -105,8 +106,10 @@
 proto_icmp = socket.getprotobyname("icmp")
 proto_icmp6 = socket.getprotobyname("ipv6-icmp")
 
+SocketAddress = Union[Tuple[str, int], Tuple[str, int, int, int]]
 
-def checksum(buffer):
+
+def checksum(buffer: bytes) -> int:
     """
     I'm not too confident that this is right but testing seems
     to suggest that it gives the same answers as in_cksum in ping.c
@@ -138,7 +141,7 @@ def checksum(buffer):
     return answer
 
 
-async def receive_one_ping(my_socket, id_, timeout):
+async def receive_one_ping(my_socket: socket.socket, id_: int, timeout: Union[int, float]) -> float:
     """
     receive the ping from the socket.
     :param my_socket:
@@ -153,7 +156,7 @@ async def receive_one_ping(my_socket, id_, timeout):
             while True:
                 rec_packet = await loop.sock_recv(my_socket, 1024)
 
-                # No IP Header when unpriviledged on Linux
+                # No IP Header when unprivileged on Linux
                 has_ip_header = (
                     (os.name != "posix")
                     or (platform.system() == "Darwin")
@@ -176,7 +179,7 @@ async def receive_one_ping(my_socket, id_, timeout):
                 if type != ICMP_ECHO_REPLY and type != ICMP6_ECHO_REPLY:
                     continue
 
-                if not has_ip_header:  
+                if not has_ip_header:
                     # When unprivileged on Linux, ICMP ID is rewrited by kernel
                     # According to https://stackoverflow.com/a/14023878/4528364
                     id_ = int.from_bytes(my_socket.getsockname()[1].to_bytes(2, "big"), "little")
@@ -195,9 +198,9 @@ async def receive_one_ping(my_socket, id_, timeout):
         raise TimeoutError("Ping timeout")
 
 
-def sendto_ready(packet, socket, future, dest):
+def sendto_ready(packet: bytes, socket: socket.socket, future: asyncio.Future, dest_addr: SocketAddress):
     try:
-        socket.sendto(packet, dest)
+        socket.sendto(packet, dest_addr)
     except (BlockingIOError, InterruptedError):
         return  # The callback will be retried
     except Exception as exc:
@@ -208,13 +211,12 @@ def sendto_ready(packet, socket, future, dest):
         future.set_result(None)
 
 
-async def send_one_ping(my_socket, dest_addr, id_, timeout, family):
+async def send_one_ping(my_socket: socket.socket, dest_addr: SocketAddress, id_: int, family: Optional[socket.AddressFamily] = None):
     """
     Send one ping to the given >dest_addr<.
     :param my_socket:
     :param dest_addr:
     :param id_:
-    :param timeout:
     :return:
     """
     icmp_type = ICMP_ECHO_REQUEST if family == socket.AddressFamily.AF_INET\
@@ -240,13 +242,13 @@ async def send_one_ping(my_socket, dest_addr, id_, timeout, family):
     packet = header + data
 
     future = asyncio.get_event_loop().create_future()
-    callback = functools.partial(sendto_ready, packet=packet, socket=my_socket, dest=dest_addr, future=future)
+    callback = functools.partial(sendto_ready, packet=packet, socket=my_socket, dest_addr=dest_addr, future=future)
     asyncio.get_event_loop().add_writer(my_socket, callback)
 
     await future
 
 
-async def ping(dest_addr, timeout=10, family=None):
+async def ping(dest_addr: Union[str, bytes], timeout: Union[int, float] = 10.0, family: Optional[socket.AddressFamily] = None) -> float:
     """
     Returns either the delay (in seconds) or raises an exception.
     :param dest_addr:
@@ -292,14 +294,14 @@ async def ping(dest_addr, timeout=10, family=None):
 
     my_id = uuid.uuid4().int & 0xFFFF
 
-    await send_one_ping(my_socket, addr, my_id, timeout, family)
+    await send_one_ping(my_socket, addr, my_id, family)
     delay = await receive_one_ping(my_socket, my_id, timeout)
     my_socket.close()
 
     return delay
 
 
-async def verbose_ping(dest_addr, timeout=2, count=3, family=None):
+async def verbose_ping(dest_addr: Union[str, bytes], timeout=2.0, count=3, family: Optional[socket.AddressFamily] = None):
     """
     Send >count< ping to >dest_addr< with the given >timeout< and display
     the result.
@@ -313,7 +315,7 @@ async def verbose_ping(dest_addr, timeout=2, count=3, family=None):
 
         try:
             delay = await ping(dest_addr, timeout, family)
-        except TimeoutError as e:
+        except TimeoutError:
             logger.error("%s timed out after %ss" % (dest_addr, timeout))
         except Exception as e:
             logger.error("%s failed: %s" % (dest_addr, str(e)))