1 files changed, 2 insertions, 0 deletions
diff --git a/tanken.py b/tanken.py
index a9468b0..2ca80bd 100644
--- a/tanken.py
+++ b/tanken.py
@@ -23,6 +23,8 @@ def tanken(drives, cost):
                 passengers[p][0] += d[0]
    
     # calculate cost per kilometer
+    if distance <= 0:
+        return None, "Driven distance must be greater than 0!"
     c = cost/distance
 
     for d in drives: