diff --git a/plugins/woocommerce/changelog/43448-fix-logging-php-deprecated-warning b/plugins/woocommerce/changelog/43448-fix-logging-php-deprecated-warning
new file mode 100644
index 00000000000..638e3788fff
--- /dev/null
+++ b/plugins/woocommerce/changelog/43448-fix-logging-php-deprecated-warning
@@ -0,0 +1,4 @@
+Significance: patch
+Type: fix
+Comment: Fixes a PHP deprecation warning introduced in PR-42979.
+
diff --git a/plugins/woocommerce/includes/class-wc-log-levels.php b/plugins/woocommerce/includes/class-wc-log-levels.php
index 80ca513ebfc..19737d9e066 100644
--- a/plugins/woocommerce/includes/class-wc-log-levels.php
+++ b/plugins/woocommerce/includes/class-wc-log-levels.php
@@ -78,7 +78,7 @@ abstract class WC_Log_Levels {
 	 * @return bool True if $level is a valid level.
 	 */
 	public static function is_valid_level( $level ) {
-		return array_key_exists( strtolower( $level ), self::$level_to_severity );
+		return is_string( $level ) && array_key_exists( strtolower( $level ), self::$level_to_severity );
 	}
 
 	/**