diff --git a/pySOT/surrogate/surrogate.py b/pySOT/surrogate/surrogate.py
index 89edafd..107fc6c 100644
--- a/pySOT/surrogate/surrogate.py
+++ b/pySOT/surrogate/surrogate.py
@@ -56,11 +56,10 @@ def add_points(self, xx, fx):
         :param xx: Points to add
         :type xx: numpy.ndarray
         :param fx: The function values of the point to add
-        :type fx: numpy.array or float
+        :type fx: array-like or scalar
         """
         xx = np.atleast_2d(xx)
-        if isinstance(fx, float):
-            fx = np.array([fx])
+        fx = np.asarray(fx)
         if fx.ndim == 0:
             fx = np.expand_dims(fx, axis=0)
         if fx.ndim == 1:
diff --git a/tests/test_surrogates.py b/tests/test_surrogates.py
index 3cfbf97..f6ae282 100644
--- a/tests/test_surrogates.py
+++ b/tests/test_surrogates.py
@@ -163,6 +163,15 @@ def test_rbf():
     assert la.norm(df(np.atleast_2d(X[0, :])) - dfhx) < 1e-1
 
 
+def test_add_points_accepts_integer_function_value():
+    rbf = RBFInterpolant(dim=2, lb=np.zeros(2), ub=np.ones(2))
+
+    rbf.add_points(np.array([0.25, 0.75]), 1)
+
+    assert rbf.fX.shape == (1, 1)
+    np.testing.assert_allclose(rbf.fX, np.array([[1.0]]))
+
+
 def test_gp():
     X = make_grid(30)  # Make uniform grid with 30 x 30 points
     gp = GPRegressor(dim=2, lb=np.zeros(2), ub=np.ones(2))