diff --git a/module03/subject/en.subject.tex b/module03/subject/en.subject.tex
index 26dd7b8..e11ff2d 100644
--- a/module03/subject/en.subject.tex
+++ b/module03/subject/en.subject.tex
@@ -668,8 +668,9 @@ \section*{Instructions}
     -----
         array: numpy.ndarray corresponding to the image.
         filter: string with accepted values in ['m','mean','w','weight']
-        weights: [kwargs] list of 3 floats where the sum equals to 1,
+        weights: [kwargs] 3 floats where the sum equals to 1,
                  corresponding to the weights of each RBG channels.
+		 expecting keys: 'r_weight', 'g_weight' and 'b_weight'.
     Return:
     -------
         array: numpy.ndarray corresponding to the transformed image.
@@ -739,7 +740,7 @@ \section*{Examples}
 
 cf.to_grayscale(arr, 'm')
 
-cf.to_grayscale(arr, 'weight', weights = [0.2, 0.3, 0.5])
+cf.to_grayscale(arr, 'weight', r_weight=0.2, 'g_weight'=0.3, 'b_weight'=0.5)
 \end{minted}
 
 \begin{figure}[h!]
diff --git a/version b/version
index 903cd9f..f89d7c7 100644
--- a/version
+++ b/version
@@ -1 +1 @@
-v3.1.1
+v3.1.3
\ No newline at end of file