diff --git a/clients/src/main/java/org/apache/kafka/common/config/AbstractConfig.java b/clients/src/main/java/org/apache/kafka/common/config/AbstractConfig.java
index 819770b28275f..3832603222a65 100644
--- a/clients/src/main/java/org/apache/kafka/common/config/AbstractConfig.java
+++ b/clients/src/main/java/org/apache/kafka/common/config/AbstractConfig.java
@@ -352,7 +352,7 @@ private void logAll() {
      */
     public void logUnused() {
         for (String key : unused())
-            log.warn("The configuration '{}' was supplied but isn't a known config.", key);
+            log.debug("The configuration '{}' was supplied but isn't a known config.", key);
     }
 
     private <T> T getConfiguredInstance(Object klass, Class<T> t, Map<String, Object> configPairs) {