diff --git a/src/main/java/cz/trask/migration/AbstractProcess.java b/src/main/java/cz/trask/migration/AbstractProcess.java
index ca345ea..21db0a6 100644
--- a/src/main/java/cz/trask/migration/AbstractProcess.java
+++ b/src/main/java/cz/trask/migration/AbstractProcess.java
@@ -86,7 +86,7 @@ public abstract class AbstractProcess {
 		yamlFactory.configure(YAMLGenerator.Feature.MINIMIZE_QUOTES, true);
 		yamlFactory.configure(YAMLGenerator.Feature.SPLIT_LINES, false);
 		mapperYaml = new ObjectMapper(yamlFactory);
-		mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+		mapperYaml.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
 
 		config = ConfigManager.getInstance().getConfig();