The Amazon e-commerce company isn’t liable for enabling illegal agricultural imports by providing a “neutral service” to online sellers who violate the law, according to a federal appeals court.

The U.S. Court of Appeals for the D.C. Circuit has overturned a $1 million penalty that the U.S. Department of Agriculture imposed on Amazon, ruling that the retail giant didn’t knowingly participate in unlawfully shipping animal and plant products.

“The mere operation of a neutral fulfillment service that makes it easier for third-party sellers to import products into the United States — and even to do so unlawfully —is not conscious and culpable involvement in the wrongdoing,” the appellate ruling said.

Over several years, the USDA’s Animal and Plant Health Inspection Service seized beef, pork and poultry products from China and lime leaves from Thailand that were headed to an Amazon fulfillment center, which helps distribute goods to U.S. consumers.

The USDA decided that Amazon was involved in illegally importing the agricultural products by “aiding, abetting, causing, or inducing” the shipments, resulting in a $500,000 fine for violating animal health regulations and another $500,000 fine for violating plant protection rules.

According to USDA, such unlawful imports endanger U.S. farmers and public health by potentially introducing avian influenza, swine fever, foot-and-mouth disease, citrus canker disease and other pathogens. The shipments in question were disguised as packages of rubber tubing, plastic strips, gift boxes and personal belongings.

“The specific regulations violated here aim to prevent outbreaks of diseases which could result, or have previously resulted, in devastating economic losses,” according to USDA’s court filing. “That is why Congress has made it incumbent on all those who play a role in the importation of plant and animal products to ensure that they actively work to prevent potentially devastating outbreaks by ensuring compliance with the Secretary’s regulations.”

Amazon challenged the USDA’s civil penalties, arguing the agency “applied an unprecedented and incorrect construction” of animal and plant health regulations, because only the third-party sellers were at fault for the illegal imports.

“The sellers handled all aspects of shipping the products into the United States. Amazon did not ship them or transport them into the United States, and was not the importer of record. It was the addressee,” according to Amazon’s court filing.

Beyond the impacts to Amazon, the company said the USDA’s “expanded” definition of liability “would ensnare many other innocent actors,” such as customs brokers, shipping logistics providers and transportation companies.

The USDA countered that third-party sellers are required to register their online products with Amazon, making the company aware of the goods that will be shipped to its warehouses for distribution to consumers.

While the size of the civil penalty wouldn’t impair Amazon’s ability to do business — the company earned roughly $30 billion in profits on $575 billion in sales in its most recent fiscal year — the $1 million fine helps deter Amazon and others from similar violations, the agency said.

According to USDA, Amazon exercises control over the products offered by third-party sellers in the U.S. by handling their storage and key elements of the shipping process, which can induce the unlawful importation of agricultural products.

Though the company is aware of the products being sent to its warehouses, it doesn’t determine whether they’ve been lawfully imported, and instead purports to shift that duty entirely to third-party sellers, the agency said.

“Notwithstanding Amazon’s efforts to escape responsibility for its role, Amazon plainly played an essential role in the importation of the animal and plant products at issue here,” the USDA said. ”Amazon contracted to receive those products into inventory for further sale; accepted those products into its program when they were registered; instructed third-party sellers to ship those products to Amazon warehouses in the United States; and promised that if they did so, Amazon would handle virtually all aspects of the domestic transaction.”

The D.C. Circuit Court of Appeals has disagreed with the USDA’s interpretation of the law, finding the agency lacked evidence of Amazon’s “knowing and substantial assistance” in violating the Animal Health Protection Act and Plant Protection Act.

The appellate court also dismissed USDA’s arguments that it should defer to the agency interpretation of culpability under the laws. A legal precedent that required courts to accept a federal agency’s reasonable interpretation of an ambiguous statute, known as Chevron deference, was recently overturned by the U.S. Supreme Court.