diff --git a/httping.py b/httping.py
index eca53cc..40555cd 100755
--- a/httping.py
+++ b/httping.py
@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 
 """Simulates httping for `argos <https://github.com/p-e-w/argos>`."""
+
 # <bitbar.title>httping</bitbar.title>
 # <bitbar.version>v1.0</bitbar.version>
 # <bitbar.author>Tobias Schmidl</bitbar.author>
@@ -11,13 +12,14 @@
 # <bitbar.dependencies>python,requests</bitbar.dependencies>
 # <bitbar.abouturl>https://github.com/schtobia/argos-httping/blob/master/httping.py</bitbar.abouturl>
 
+from __future__ import annotations
+
 import datetime  # for the whole ms → s and vice versa stuff
 import statistics  # for median and stdev
 import sys  # for redirecting print to stderr
+from typing import Generic, List, Sequence, TypeVar, Optional, Tuple, Dict, Union
 
 import requests  # for the central HTTP HEAD request
-from typing import (List)
-from __future__ import annotations
 
 __author__ = "Tobias Schmidl"
 __copyright__ = "Copyright 2018, Tobias Schmidl"
@@ -25,31 +27,35 @@ __license__ = "MIT"
 __version__ = "0.0.1"
 __maintainer__ = "Tobias Schmidl"
 
-MAX_PING: int = datetime.timedelta(milliseconds=1000)  # in seconds
+MAX_PING: datetime.timedelta = datetime.timedelta(milliseconds=1000)  # in seconds
 TARGETS: List[str] = ["https://www.google.de", "https://www.bing.com", "https://www.wikipedia.org"]
 
-MAX_PING_IN_MS: int = MAX_PING.total_seconds() * 1000
+T = TypeVar('T')
+Bucket = Tuple[int, int]
+BucketList = List[Bucket]
+
+MAX_PING_IN_MS: int = int(MAX_PING.total_seconds() * 1000)
 
 
-def in_bucket(element, bucket):
+def in_bucket(element: int, bucket: Bucket) -> bool:
     """Return True if element is in bucket."""
     return bucket[0] <= element <= bucket[1]
 
 
-def generate_buckets(min_val, max_val, step_width=2):
+def generate_buckets(min_val: int, max_val: int, step_width: int = 2) -> BucketList:
     """Generate a list of partitioned lists between min_val and max_val."""
-    return [[x, x + step_width - 1] for x in range(min_val, max_val, step_width)]
+    return [(x, x + step_width - 1) for x in range(min_val, max_val, step_width)]
 
 
 class Themes:
     """Maintain a list of themes and generates buckets between 0 and MAX_PING_IN_MS based on the selected theme."""
 
     # Themes are from http://colorbrewer2.org/
-    purple_green = ["#762a83", "#9970ab", "#c2a5cf", "#a6dba0", "#5aae61", "#1b7837"]
-    red_green = ["#d73027", "#fc8d59", "#fee08b", "#d9ef8b", "#91cf60", "#1a9850"]
-    original = ["#acacac", "#ff0101", "#cc673b", "#ce8458", "#6bbb15", "#0ed812"]
-    selected_colors = None
-    buckets = None
+    purple_green: List[str] = ["#762a83", "#9970ab", "#c2a5cf", "#a6dba0", "#5aae61", "#1b7837"]
+    red_green: List[str] = ["#d73027", "#fc8d59", "#fee08b", "#d9ef8b", "#91cf60", "#1a9850"]
+    original: List[str] = ["#acacac", "#ff0101", "#cc673b", "#ce8458", "#6bbb15", "#0ed812"]
+    selected_colors: List[str] = []
+    buckets: BucketList = []
 
     def __init__(self, selected_colors):
         """Initialize class with a selected theme."""
@@ -64,12 +70,12 @@ class Themes:
         return self.selected_colors[0]
 
 
-CURRENT_THEME = Themes(Themes.red_green)
+CURRENT_THEME: Themes = Themes(Themes.red_green)
 
 
-def httping(targets):
+def httping(targets: List[str]) -> Tuple[Dict[str, Optional[float]], Optional[float], Optional[float]]:
     """Pings the supplied targets and returns a mean and a std deviation over all target responses."""
-    responses = {}
+    responses: Dict[str, Optional[float]] = {}
     for target in targets:
         try:
             responses[target] = requests.head(target, timeout=MAX_PING.total_seconds()).elapsed.total_seconds() * 1000
@@ -89,7 +95,8 @@ def httping(targets):
 if __name__ == "__main__":
     responses, median, stddev = httping(TARGETS)
     if isinstance(median, float) and median != MAX_PING_IN_MS:
-        print("⦿ " + str(round(median, 2)) + "±" + str(round(stddev, 2)) + " | color=" + CURRENT_THEME.colorize(median))
+        print("⦿ " + str(round(median, 2)) + "±" + str(round(stddev, 2)) + " | color=" +
+              CURRENT_THEME.colorize(median))  # type: ignore
     else:
         print("☠ | color=" + CURRENT_THEME.selected_colors[0])
     print("---")