diff --git a/src/Product/WCProductAdapter.php b/src/Product/WCProductAdapter.php
index 521e395dbe..42717f1222 100644
--- a/src/Product/WCProductAdapter.php
+++ b/src/Product/WCProductAdapter.php
@@ -572,6 +572,12 @@ protected function map_wc_shipping_weight( string $unit = 'g' ): WCProductAdapte
 		}
 
 		$weight = wc_get_weight( $this->wc_product->get_weight(), $unit );
+
+		// Use lb if the unit is lbs, since GMC uses lb.
+		if ( 'lbs' === $unit ) {
+			$unit = 'lb';
+		}
+
 		$this->setShippingWeight(
 			new GoogleProductShippingWeight(
 				[
diff --git a/tests/Unit/Product/WCProductAdapterTest.php b/tests/Unit/Product/WCProductAdapterTest.php
index a1e50ceb85..290abb571b 100644
--- a/tests/Unit/Product/WCProductAdapterTest.php
+++ b/tests/Unit/Product/WCProductAdapterTest.php
@@ -930,6 +930,28 @@ public function test_shipping_dimensions_and_weight_units_use_default_if_wc_opti
 		$this->assertEquals( 1000, $adapted_product->getShippingWeight()->getValue() );
 	}
 
+	public function test_shipping_weight_unit_uses_lb_if_wc_option_is_lbs() {
+		update_option( 'woocommerce_weight_unit', 'lbs' );
+
+		$product = WC_Helper_Product::create_simple_product(
+			false,
+			[
+				'height' => '3',
+				'length' => '4',
+				'width'  => '5',
+				'weight' => '1',
+			]
+		);
+
+		$adapted_product = new WCProductAdapter(
+			[
+				'wc_product'    => $product,
+				'targetCountry' => 'US',
+			]
+		);
+		$this->assertEquals( 'lb', $adapted_product->getShippingWeight()->getUnit() );
+	}
+
 	/**
 	 * @param array $shipping_dimensions
 	 *