generics for string lists
diff --git a/src/main/java/org/apache/log4j/spi/LoggingEventFieldResolver.java b/src/main/java/org/apache/log4j/spi/LoggingEventFieldResolver.java
index 6bc2315..7bca2f1 100644
--- a/src/main/java/org/apache/log4j/spi/LoggingEventFieldResolver.java
+++ b/src/main/java/org/apache/log4j/spi/LoggingEventFieldResolver.java
@@ -65,7 +65,7 @@
     /**
      * Keyword list.
      */
-    public static final List KEYWORD_LIST = new ArrayList();
+    public static final List<String> KEYWORD_LIST = new ArrayList<>();
     /**
      * LOGGER string literal.
      */