diff --git a/core/dtn7/src/dtnconfig.rs b/core/dtn7/src/dtnconfig.rs
index 76e527e4..e2f39862 100644
--- a/core/dtn7/src/dtnconfig.rs
+++ b/core/dtn7/src/dtnconfig.rs
@@ -64,13 +64,18 @@ pub fn rnd_node_name() -> String {
 impl From<PathBuf> for DtnConfig {
     fn from(item: PathBuf) -> Self {
         let mut dtncfg = DtnConfig::new();
-        let mut s = Config::default();
+        let s_default = Config::default();
+
+        let configbuilder = Config::builder().add_source(s_default);
 
         debug!("Loading config: {}", item.to_str().unwrap());
 
         // Start off by merging in the "default" configuration file
-        s.merge(File::new(item.to_str().unwrap(), config::FileFormat::Toml))
+        let s = configbuilder
+            .add_source(File::new(item.to_str().unwrap(), config::FileFormat::Toml))
+            .build()
             .unwrap();
+
         dtncfg.debug = s.get_bool("debug").unwrap_or(false);
         if dtncfg.debug {
             //std::env::set_var("RUST_LOG", "dtn7=debug,dtnd=debug");
diff --git a/core/dtn7/tests/config-test.rs b/core/dtn7/tests/config-test.rs
index f23bc9c9..f1941c1b 100644
--- a/core/dtn7/tests/config-test.rs
+++ b/core/dtn7/tests/config-test.rs
@@ -2,14 +2,16 @@ use config::{Config, File};
 
 #[test]
 fn config_test() {
-    let mut s = Config::default();
-
     // Start off by merging in the "default" configuration file
-    s.merge(File::new(
-        "../../examples/dtn7.toml.example",
-        config::FileFormat::Toml,
-    ))
-    .unwrap();
+    let s = Config::builder()
+        .add_source(Config::default())
+        .add_source(File::new(
+            "../../examples/dtn7.toml.example",
+            config::FileFormat::Toml,
+        ))
+        .build()
+        .unwrap();
+
     println!("{:?}", s);
 
     println!("debug: {:?}", s.get_bool("debug").unwrap_or(false));