diff --git a/causalml/inference/tree/uplift.pyx b/causalml/inference/tree/uplift.pyx
index 1f60b908..272e2ae5 100644
--- a/causalml/inference/tree/uplift.pyx
+++ b/causalml/inference/tree/uplift.pyx
@@ -33,6 +33,7 @@ from joblib import Parallel, delayed
 from packaging import version
 from sklearn.model_selection import train_test_split
 from sklearn.utils import check_X_y, check_array, check_random_state
+import numbers
 
 if version.parse(sklearn.__version__) >= version.parse('0.22.0'):
     from sklearn.utils._testing import ignore_warnings
@@ -2264,7 +2265,7 @@ class UpliftTreeClassifier:
             else:
                 v = observations[tree.col]
                 branch = None
-                if isinstance(v, int) or isinstance(v, float):
+                if isinstance(v, numbers.Number):
                     if v >= tree.value:
                         branch = tree.trueBranch
                     else:
@@ -2311,7 +2312,7 @@ class UpliftTreeClassifier:
                     return dict(result)
                 else:
                     branch = None
-                    if isinstance(v, int) or isinstance(v, float):
+                    if isinstance(v, numbers.Number):
                         if v >= tree.value:
                             branch = tree.trueBranch
                         else: