This paper introduces a novel method for composing Web services in the presence of external volatile information. Our approach, which we call the informed-presumptive, is compared to previous state-of-the-art approaches for Web service composition in volatile environments. We show empirically that the informed-presumptive strategy produces compositions in significantly less time than the other strategies with lesser backtracks. Categories and Subject Descriptors H.3.5 [Online Information Systems]: Web-based Services General Terms Algorithms, Theory Keywords Web services, Adaptation, Volatile environments, Expiration times