diff --git a/python-package/xgboost/sklearn.py b/python-package/xgboost/sklearn.py
index 1f3033f2d29e..f533f7f3477d 100644
--- a/python-package/xgboost/sklearn.py
+++ b/python-package/xgboost/sklearn.py
@@ -77,7 +77,7 @@ def inner(preds, dmatrix):
     gamma : float
         Minimum loss reduction required to make a further partition on a leaf
         node of the tree.
-    min_child_weight : int
+    min_child_weight : float
         Minimum sum of instance weight(hessian) needed in a child.
     max_delta_step : int
         Maximum delta step we allow each tree's weight estimation to be.