diff --git a/src/test/java/com/logtail/logback/LogtailAppenderBatchConfigSizeTest.java b/src/test/java/com/logtail/logback/LogtailAppenderBatchConfigSizeTest.java
index 25ef39c..c9af9bf 100644
--- a/src/test/java/com/logtail/logback/LogtailAppenderBatchConfigSizeTest.java
+++ b/src/test/java/com/logtail/logback/LogtailAppenderBatchConfigSizeTest.java
@@ -60,10 +60,13 @@ public void testBatchSizeFromConfig() throws Exception {
         MDC.put("requestId", "testErrorLog");
         MDC.put("requestTime", 199 + "");
         this.logger.info(batchRunId + " Custom batch size Final Batch Groot ");
-        Thread.sleep(4000);
-        assertEquals(1, this.appender.apiCalls);
+
+        // The 200th line sends the batch on another thread. Wait for that flush instead of a fixed time: a request to
+        // the real endpoint now and then takes several seconds, or fails and is retried by the appender
+        this.appender.awaitFlushCompletion();
 
         isOk();
+        assertEquals(1, this.appender.acceptedCalls);
     }
 
     private void isOk() {
diff --git a/src/test/java/com/logtail/logback/LogtailAppenderDecorator.java b/src/test/java/com/logtail/logback/LogtailAppenderDecorator.java
index 77f0040..99fb8eb 100644
--- a/src/test/java/com/logtail/logback/LogtailAppenderDecorator.java
+++ b/src/test/java/com/logtail/logback/LogtailAppenderDecorator.java
@@ -9,12 +9,17 @@ public class LogtailAppenderDecorator extends LogtailAppender {
     private Exception exception;
     private LogtailResponse response;
     protected int apiCalls = 0;
+    // Calls answered with 202, i.e. apiCalls without the failed ones the appender retried
+    protected int acceptedCalls = 0;
 
     @Override
     protected LogtailResponse callHttpURLConnection(int flushedSize) throws IOException {
         try {
             apiCalls++;
             this.response = super.callHttpURLConnection(flushedSize);
+            if (isOK()) {
+                acceptedCalls++;
+            }
 
             return this.response;
         } catch (Exception e) {