Let A ⊆ B be a commutative ring extension. Let I(A, B) be the multiplicative group of invertible A-submodules of B. In this article, we extend a result of Sadhu and Singh by finding a necessary and sufficient condition on an integral birational extension A ⊆ B of integral domains with dim A ≤ 1, so that the natural map I(A, B) → I(A[X, X −1 ], B[X, X −1 ]) is an isomorphism. In the same situation, we show that if dim A ≥ 2, then the condition is necessary but not sufficient. We also discuss some properties of the cokernel of the natural map I(A, B) → I(A[X, X −1 ], B[X, X −1 ]) in the general case.