diff --git a/pokemongo_bot/constants.py b/pokemongo_bot/constants.py
index 43352ae576..70912e8409 100644
--- a/pokemongo_bot/constants.py
+++ b/pokemongo_bot/constants.py
@@ -1,3 +1,2 @@
 class Constants(object):
     MAX_DISTANCE_FORT_IS_REACHABLE = 40 # meters
-    NORMALIZED_LAT_LNG_DISTANCE_STEP = 6.3593e-6
diff --git a/pokemongo_bot/step_walker.py b/pokemongo_bot/step_walker.py
index b39cb4ce9d..ca7d50eec7 100644
--- a/pokemongo_bot/step_walker.py
+++ b/pokemongo_bot/step_walker.py
@@ -1,7 +1,7 @@
 from math import sqrt
 
 from pokemongo_bot import logger
-from cell_workers.utils import distance, i2f
+from cell_workers.utils import distance, i2f, float_equal
 from human_behaviour import random_lat_long_delta, sleep
 import sys
 
@@ -36,6 +36,12 @@ def __init__(self, bot, speed, destLat, destLng):
         else:
             self.dLat = (destLat - self.initLat) / int(self.steps)
             self.dLng = (destLng - self.initLng) / int(self.steps)
+
+            if float_equal(self.dLat, 0) or float_equal(self.dLng, 0):
+                # the distance is too big
+                raise RuntimeError("lat: {}, lng: {} aren't valid (too far) - dist = {}"
+                    .format(destLat, destLng, self.dist))
+
             self.magnitude = self._pythagorean(self.dLat, self.dLng)
 
     def step(self):
diff --git a/tests/test_step_walker.py b/tests/test_step_walker.py
index dace9b1808..9d3dc52f67 100644
--- a/tests/test_step_walker.py
+++ b/tests/test_step_walker.py
@@ -5,6 +5,8 @@
 from pokemongo_bot.constants import Constants
 from pokemongo_bot.cell_workers.utils import float_equal
 
+NORMALIZED_LAT_LNG_DISTANCE_STEP = 6.3593e-6
+
 class TestStepWalker(object):
     def setup(self):
         self.patcherSleep = patch('pokemongo_bot.step_walker.sleep')
@@ -33,8 +35,8 @@ def test_normalized_distance(self):
         flag = sw.step()
         ok_(flag != True)
 
-        ok_(float_equal(self.lat, Constants.NORMALIZED_LAT_LNG_DISTANCE_STEP))
-        ok_(float_equal(self.lng, Constants.NORMALIZED_LAT_LNG_DISTANCE_STEP))
+        ok_(float_equal(self.lat, NORMALIZED_LAT_LNG_DISTANCE_STEP))
+        ok_(float_equal(self.lng, NORMALIZED_LAT_LNG_DISTANCE_STEP))
 
     def test_normalized_distance_times_2(self):
         sw = StepWalker(self.bot, 2, 0.1, 0.1)
@@ -44,8 +46,8 @@ def test_normalized_distance_times_2(self):
         flag = sw.step()
         ok_(flag != True)
 
-        ok_(float_equal(self.lat, Constants.NORMALIZED_LAT_LNG_DISTANCE_STEP * 2))
-        ok_(float_equal(self.lng, Constants.NORMALIZED_LAT_LNG_DISTANCE_STEP * 2))
+        ok_(float_equal(self.lat, NORMALIZED_LAT_LNG_DISTANCE_STEP * 2))
+        ok_(float_equal(self.lng, NORMALIZED_LAT_LNG_DISTANCE_STEP * 2))
 
     def test_small_distance_same_spot(self):
         sw = StepWalker(self.bot, 1, 0, 0)
@@ -61,12 +63,6 @@ def test_small_distance_small_step(self):
         ok_(sw.dLat == 0)
         ok_(sw.dLng == 0)
 
-
+    @raises(RuntimeError)
     def test_big_distances(self):
-        ### BUG
-
         sw = StepWalker(self.bot, 1, 10, 10)
-        ok_(sw.dLat == 0)
-        ok_(sw.dLng == 0)
-
-        ## this test should pass ? if the distance is too big, the bot doesn't move