diff --git a/Server/src/main/java/org/openas2/processor/msgtracking/DbTrackingModule.java b/Server/src/main/java/org/openas2/processor/msgtracking/DbTrackingModule.java
index 34735c82..87df5a51 100644
--- a/Server/src/main/java/org/openas2/processor/msgtracking/DbTrackingModule.java
+++ b/Server/src/main/java/org/openas2/processor/msgtracking/DbTrackingModule.java
@@ -65,7 +65,8 @@ public void init(Session session, Map<String, String> options) throws OpenAS2Exc
         dbPwd = getParameter(PARAM_DB_PWD, true);
         configBaseDir = session.getBaseDirectory();
         jdbcConnectString = getParameter(PARAM_JDBC_CONNECT_STRING, true);
-        jdbcConnectString.replace("%home%", configBaseDir);
+        // String is immutable - assign the result or the substitution is lost
+        jdbcConnectString = jdbcConnectString.replace("%home%", configBaseDir);
         // Support component attributes in connect string
         jdbcConnectString = ParameterParser.parse(jdbcConnectString, paramParser);
         dbPlatform = jdbcConnectString.replaceAll(".*jdbc:([^:]*):.*", "$1");