diff --git a/includes/class-wc-cart.php b/includes/class-wc-cart.php
index c99fd0c5a8b..b9d67571b57 100644
--- a/includes/class-wc-cart.php
+++ b/includes/class-wc-cart.php
@@ -1890,12 +1890,12 @@ class WC_Cart {
 					$discount_amount = min( $price, $discount_amount );
 					$price           = max( $price - $discount_amount, 0 );
 
-					// Store the totals for DISPLAY in the cart
+					// Store the totals for DISPLAY in the cart.
 					if ( $add_totals ) {
 						$total_discount     = $discount_amount * $values['quantity'];
 						$total_discount_tax = 0;
 
-						if ( wc_tax_enabled() ) {
+						if ( wc_tax_enabled() && $product->is_taxable() ) {
 							$tax_rates          = WC_Tax::get_rates( $product->get_tax_class() );
 							$taxes              = WC_Tax::calc_tax( $discount_amount, $tax_rates, $this->prices_include_tax );
 							$total_discount_tax = WC_Tax::get_tax_total( $taxes ) * $values['quantity'];