diff --git a/exercises/concept/wellingtons-weather-station/.docs/introduction.md b/exercises/concept/wellingtons-weather-station/.docs/introduction.md
index 8883926d..87a5027c 100644
--- a/exercises/concept/wellingtons-weather-station/.docs/introduction.md
+++ b/exercises/concept/wellingtons-weather-station/.docs/introduction.md
@@ -101,6 +101,9 @@ The `%` operator is used for modulus.
 
 5 % 3
 # => 2
+
+-7 % 5
+# => 3
 ```
 
 ~~~~exercism/caution
@@ -111,6 +114,13 @@ This is different from normal division.
 1 % 0
 # Error: Unhandled exception: Division by 0 (DivisionByZeroError)
 ```
+
+Note that unlike some other programming languages crystal is using floored division to calculate modulus (in JavaScript this would yield -1)
+
+```crystal
+-6 % 5 
+# => 4
+```
 ~~~~
 
 ## Rounding