diff --git a/bifromq-mqtt/bifromq-mqtt-server/src/main/java/org/apache/bifromq/mqtt/handler/MQTTSessionHandler.java b/bifromq-mqtt/bifromq-mqtt-server/src/main/java/org/apache/bifromq/mqtt/handler/MQTTSessionHandler.java
index 02f3ece33..d15aee9cd 100644
--- a/bifromq-mqtt/bifromq-mqtt-server/src/main/java/org/apache/bifromq/mqtt/handler/MQTTSessionHandler.java
+++ b/bifromq-mqtt/bifromq-mqtt-server/src/main/java/org/apache/bifromq/mqtt/handler/MQTTSessionHandler.java
@@ -166,7 +166,7 @@
 @Slf4j
 public abstract class MQTTSessionHandler extends MQTTMessageHandler implements IMQTTSession {
     protected static final boolean SANITY_CHECK = SanityCheckMqttUtf8String.INSTANCE.get();
-    private static final double EMA_APLHA = 0.15;
+    private static final double EMA_ALPHA = 0.15;
     private static final int REDIRECT_CHECK_INTERVAL_SECONDS = ClientRedirectCheckIntervalSeconds.INSTANCE.get();
     protected final TenantSettings settings;
     protected final String userSessionId;
@@ -370,7 +370,7 @@ public void handlerAdded(ChannelHandlerContext ctx) {
         ChannelAttrs.trafficShaper(ctx).setWriteLimit(settings.outboundBandwidth);
         ChannelAttrs.trafficShaper(ctx).setMaxWriteSize(settings.outboundBandwidth);
         ChannelAttrs.setMaxPayload(settings.maxPacketSize, ctx);
-        receiveQuota = new AdaptiveReceiveQuota(settings.minSendPerSec, clientReceiveMaximum(), EMA_APLHA);
+        receiveQuota = new AdaptiveReceiveQuota(settings.minSendPerSec, clientReceiveMaximum(), EMA_ALPHA);
         sessionCtx.localSessionRegistry.add(channelId(), this);
         sessionRegistration = ChannelAttrs.mqttSessionContext(ctx).sessionDictClient
             .reg(clientInfo, (killer, redirection) -> {