diff --git a/src/core/lombok/core/configuration/ConfigurationFile.java b/src/core/lombok/core/configuration/ConfigurationFile.java
index 121ad301..8e4e687c 100644
--- a/src/core/lombok/core/configuration/ConfigurationFile.java
+++ b/src/core/lombok/core/configuration/ConfigurationFile.java
@@ -183,7 +183,7 @@ public abstract class ConfigurationFile {
 		
 		private static String replaceEnvironmentVariables(String fileName) {
 			int start = 0;
-			StringBuilder result = new StringBuilder();
+			StringBuffer result = new StringBuffer();
 			if (fileName.startsWith("~")) {
 				start = 1;
 				result.append(System.getProperty("user.home", "~"));