diff --git a/README.md b/README.md
index fcb65a6..cfc5a17 100644
--- a/README.md
+++ b/README.md
@@ -208,7 +208,7 @@ try {
 
 ## Logging
 
-If `Hypercart_Logger` (from the Hypercart Performance Monitor plugin) is present, the plugin keeps the structured payload for array-capable logger methods and JSON-serializes it only for string-only logger signatures. Otherwise the plugin falls back to `error_log()` with single-line JSON for `grep`-ability:
+If `Hypercart_Logger` (from the Hypercart Helper plugin) is present, the plugin keeps the structured payload for array-capable logger methods and JSON-serializes it only for string-only logger signatures. Otherwise the plugin falls back to `error_log()` with single-line JSON for `grep`-ability:
 
 ```
 [hypercart_query_guard][error] {"event":"query_killed","context":"admin_ajax","limit_ms":20000,"last_query":"SELECT * FROM wp_nf_transactions WHERE meta_key = '_nofraud_transaction_status_workaround'","uri":"/wp-admin/admin-ajax.php","user_id":0,"time":1745875234}
diff --git a/class-hcqg-mutex-guard.php b/class-hcqg-mutex-guard.php
index b5849a6..17bd223 100644
--- a/class-hcqg-mutex-guard.php
+++ b/class-hcqg-mutex-guard.php
@@ -414,6 +414,12 @@ private static function log( $level, array $payload ) {
 					Hypercart_Logger::info( 'query_guard', self::get_logger_payload_for_method( 'Hypercart_Logger', 'info', $payload, $encoded ) );
 					return;
 				}
+				// The Hypercart Helper logger exposes warning(); older/string-only
+				// loggers may expose warn(). Prefer warning(), fall back to warn().
+				if ( method_exists( 'Hypercart_Logger', 'warning' ) ) {
+					Hypercart_Logger::warning( 'query_guard', self::get_logger_payload_for_method( 'Hypercart_Logger', 'warning', $payload, $encoded ) );
+					return;
+				}
 				if ( method_exists( 'Hypercart_Logger', 'warn' ) ) {
 					Hypercart_Logger::warn( 'query_guard', self::get_logger_payload_for_method( 'Hypercart_Logger', 'warn', $payload, $encoded ) );
 					return;
diff --git a/hypercart-query-guard.php b/hypercart-query-guard.php
index f4feadd..4855984 100644
--- a/hypercart-query-guard.php
+++ b/hypercart-query-guard.php
@@ -1107,8 +1107,8 @@ public static function log_slow_queries() {
 		}
 
 		/**
-		 * Centralized log emitter. Prefers Hypercart_Logger if present (your
-		 * existing file-based logger from the Performance Monitor plugin),
+		 * Centralized log emitter. Prefers Hypercart_Logger if present (the
+		 * file-based logger provided by the Hypercart Helper plugin),
 		 * falls back to error_log so this MU-plugin works standalone.
 		 *
 		 * @param string $level   'info' | 'warn' | 'error'
@@ -1126,6 +1126,12 @@ private static function log( $level, array $payload ) {
 					Hypercart_Logger::info( 'query_guard', self::get_logger_payload_for_method( 'Hypercart_Logger', 'info', $payload, $message ) );
 					return;
 				}
+				// The Hypercart Helper logger exposes warning(); older/string-only
+				// loggers may expose warn(). Prefer warning(), fall back to warn().
+				if ( method_exists( 'Hypercart_Logger', 'warning' ) ) {
+					Hypercart_Logger::warning( 'query_guard', self::get_logger_payload_for_method( 'Hypercart_Logger', 'warning', $payload, $message ) );
+					return;
+				}
 				if ( method_exists( 'Hypercart_Logger', 'warn' ) ) {
 					Hypercart_Logger::warn( 'query_guard', self::get_logger_payload_for_method( 'Hypercart_Logger', 'warn', $payload, $message ) );
 					return;
diff --git a/tests/DbDropinTest.php b/tests/DbDropinTest.php
index 806612e..9612774 100644
--- a/tests/DbDropinTest.php
+++ b/tests/DbDropinTest.php
@@ -63,7 +63,7 @@ public function test_log_slow_queries_reads_hcqg_slow_queries_when_dropin_active
 		Hypercart_Query_Guard::log_slow_queries();
 
 		$this->assertCount( 1, Hypercart_Logger::$calls );
-		$this->assertSame( 'warn', Hypercart_Logger::$calls[0]['level'] );
+		$this->assertSame( 'warning', Hypercart_Logger::$calls[0]['level'] );
 		$this->assertSame( 'slow_query', Hypercart_Logger::$calls[0]['payload']['event'] );
 		$this->assertSame( 6500, Hypercart_Logger::$calls[0]['payload']['duration_ms'] );
 	}
diff --git a/tests/LoggingTest.php b/tests/LoggingTest.php
index 778b6d8..a32f5d5 100644
--- a/tests/LoggingTest.php
+++ b/tests/LoggingTest.php
@@ -62,6 +62,22 @@ public function test_log_serializes_payload_for_hypercart_logger(): void {
 		$this->assertSame( $payload, Hypercart_Logger::$calls[0]['payload'] );
 	}
 
+	public function test_warn_level_routes_to_hypercart_logger_warning(): void {
+		// Regression: slow_query events are emitted at 'warn' level. The Helper
+		// plugin's logger exposes warning(), not warn(); the bridge must map to it.
+		$payload = array(
+			'event'       => 'slow_query',
+			'duration_ms' => 14777,
+		);
+
+		$this->call( 'log', 'warn', $payload );
+
+		$this->assertCount( 1, Hypercart_Logger::$calls );
+		$this->assertSame( 'query_guard', Hypercart_Logger::$calls[0]['channel'] );
+		$this->assertSame( 'warning', Hypercart_Logger::$calls[0]['level'] );
+		$this->assertSame( $payload, Hypercart_Logger::$calls[0]['payload'] );
+	}
+
 	public function test_string_only_logger_methods_receive_json_payload(): void {
 		$payload = array(
 			'event' => 'as_throttle_observed',
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index eab0810..85d3ffc 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -314,7 +314,7 @@ class Hypercart_Logger {
 	public static function reset(): void { self::$calls = array(); }
 	public static function error( $channel, $payload ) { self::$calls[] = array( 'level' => 'error', 'channel' => $channel, 'payload' => $payload ); }
 	public static function info( $channel, $payload ) { self::$calls[] = array( 'level' => 'info', 'channel' => $channel, 'payload' => $payload ); }
-	public static function warn( $channel, $payload ) { self::$calls[] = array( 'level' => 'warn', 'channel' => $channel, 'payload' => $payload ); }
+	public static function warning( $channel, $payload ) { self::$calls[] = array( 'level' => 'warning', 'channel' => $channel, 'payload' => $payload ); }
 }
 
 $GLOBALS['wpdb'] = new WP_Stub_DB();