diff --git a/logback-appender/src/test/resources/appender-test-large-batches.xml b/logback-appender/src/test/resources/appender-test-large-batches.xml
index 4590b57..caac6d1 100644
--- a/logback-appender/src/test/resources/appender-test-large-batches.xml
+++ b/logback-appender/src/test/resources/appender-test-large-batches.xml
@@ -8,9 +8,9 @@
         <host>${loki.host}</host>
         <port>${loki.port}</port>
 
-        <encoder>
+        <efficientLayout>
             <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
-        </encoder>
+        </efficientLayout>
 
         <header>
             <name>X-Org-Id</name>
diff --git a/logback-appender/src/test/resources/appender-test-with-buffer-size-megabytes-set-to-64.xml b/logback-appender/src/test/resources/appender-test-with-buffer-size-megabytes-set-to-64.xml
index 6296203..c44ba13 100644
--- a/logback-appender/src/test/resources/appender-test-with-buffer-size-megabytes-set-to-64.xml
+++ b/logback-appender/src/test/resources/appender-test-with-buffer-size-megabytes-set-to-64.xml
@@ -6,9 +6,9 @@
         <host>${loki.host}</host>
         <port>${loki.port}</port>
 
-        <encoder>
+        <efficientLayout>
             <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
-        </encoder>
+        </efficientLayout>
 
         <header>
             <name>X-Org-Id</name>
diff --git a/logback-appender/src/test/resources/appender-test-with-buffer-size-megabytes-unset.xml b/logback-appender/src/test/resources/appender-test-with-buffer-size-megabytes-unset.xml
index 6e9255b..170d513 100644
--- a/logback-appender/src/test/resources/appender-test-with-buffer-size-megabytes-unset.xml
+++ b/logback-appender/src/test/resources/appender-test-with-buffer-size-megabytes-unset.xml
@@ -3,9 +3,9 @@
         <host>${loki.host}</host>
         <port>${loki.port}</port>
 
-        <encoder>
+        <efficientLayout>
             <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
-        </encoder>
+        </efficientLayout>
 
         <header>
             <name>X-Org-Id</name>
diff --git a/logback-appender/src/test/resources/appender-test-with-log-label-set.xml b/logback-appender/src/test/resources/appender-test-with-log-label-set.xml
index 917af93..186ef7e 100644
--- a/logback-appender/src/test/resources/appender-test-with-log-label-set.xml
+++ b/logback-appender/src/test/resources/appender-test-with-log-label-set.xml
@@ -3,9 +3,9 @@
         <host>${loki.host}</host>
         <port>${loki.port}</port>
 
-        <encoder>
+        <efficientLayout>
             <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
-        </encoder>
+        </efficientLayout>
 
         <header>
             <name>X-Org-Id</name>
diff --git a/logback-appender/src/test/resources/appender-test-with-log-label-unset.xml b/logback-appender/src/test/resources/appender-test-with-log-label-unset.xml
index 6e9255b..170d513 100644
--- a/logback-appender/src/test/resources/appender-test-with-log-label-unset.xml
+++ b/logback-appender/src/test/resources/appender-test-with-log-label-unset.xml
@@ -3,9 +3,9 @@
         <host>${loki.host}</host>
         <port>${loki.port}</port>
 
-        <encoder>
+        <efficientLayout>
             <pattern>%-4relative [%thread] %-5level %logger{35} - %msg%n</pattern>
-        </encoder>
+        </efficientLayout>
 
         <header>
             <name>X-Org-Id</name>