diff --git a/qiskit/aqua/operators/state_fns/vector_state_fn.py b/qiskit/aqua/operators/state_fns/vector_state_fn.py
index 819e955351..aaa940687a 100644
--- a/qiskit/aqua/operators/state_fns/vector_state_fn.py
+++ b/qiskit/aqua/operators/state_fns/vector_state_fn.py
@@ -66,7 +66,7 @@ def add(self, other: OperatorBase) -> OperatorBase:
         # Right now doesn't make sense to add a StateFn to a Measurement
         if isinstance(other, VectorStateFn) and self.is_measurement == other.is_measurement:
             # Covers MatrixOperator, Statevector and custom.
-            return VectorStateFn((self.coeff * self.primitive).add(other.primitive * other.coeff),
+            return VectorStateFn((self.coeff * self.primitive) + (other.primitive * other.coeff),
                                  is_measurement=self._is_measurement)
         # pylint: disable=cyclic-import,import-outside-toplevel
         from .. import SummedOp