For frequent flyers and points enthusiasts, few things sting more than a serious devaluation of a favorite airline or credit card partnership. The recent news that American Express Membership Rewards will be devaluing its transfer ratio to Emirates Skywards is exactly that—a significant blow to a once-lucrative partnership.

In what feels like a double whammy, this change comes on the heels of a confusing period in July when transfers were temporarily disabled, ostensibly for "maintenance." While some may have hoped this was a simple technical hiccup, the subsequent announcement reveals a far more serious development. Effective September 16, the transfer ratio will shift from the familiar and generous 1:1 to a disappointing 5:4. This means for every 5 Amex points you transfer, you will now only receive 4 Skywards miles, representing a straight 20% loss in value.

This change places a heavy burden on anyone looking to book aspirational awards. For example, a one-way business class ticket on a fifth-freedom route, which currently costs 87,000 Amex points, will soon require a staggering 109,000 Amex points—a difference of 22,000 points for the same flight.

While a window of opportunity exists until September 16 to transfer points at the old rate, this news serves as a stark reminder of the ever-changing landscape of rewards programs. It’s a serious devaluation that signals a broader trend in the industry, following a similar move by Citi ThankYou Rewards. As other credit card programs like Bilt Rewards, Capital One miles, and Chase Ultimate Rewards still maintain a 1:1 ratio, it remains to be seen if they will follow suit. For now, this change feels like a serious step backward for a partnership that was a cornerstone of many travel hacking strategies.