diff --git a/skrebate/relieff.py b/skrebate/relieff.py
index <HASH>..<HASH> 100644
--- a/skrebate/relieff.py
+++ b/skrebate/relieff.py
@@ -236,6 +236,8 @@ class ReliefF(BaseEstimator):
             """Normalizes continuous features so they are in the same range"""
             idx = 0
             for i in attr:
+                if attr[i][0] == 'discrete':
+                    continue
                 cmin = attr[i][2]
                 diff = attr[i][3]
                 x[:, idx] -= cmin
Bug fix for index out of range error

The pre_normalize function should only consider continuous attributes.