diff --git a/config.sample.json b/config.sample.json
index bcb0619..fd08425 100644
--- a/config.sample.json
+++ b/config.sample.json
@@ -35,7 +35,7 @@
         "SMS1"
     ],
 
-    "imsi_senders": {
+    "senders_imsi": {
         "prefix_names": {
             "TELKOMSEL": [
             ],
diff --git a/lib/modem-chooser.js b/lib/modem-chooser.js
index 91ebfe1..aa5aa27 100644
--- a/lib/modem-chooser.js
+++ b/lib/modem-chooser.js
@@ -33,13 +33,13 @@ exports.chooser = async function chooser(destination, config) {
     if (logger) logger.verbose('MODEM-CHOOSER: Choosing suitable senders', { destination, prefixName });
 
     let imsiSenders = [];
-    if (config.imsi_senders && prefixName && config.imsi_senders.prefix_names && config.imsi_senders.prefix_names[prefixName]) {
-        imsiSenders = filterOutCandidates(config.imsi_senders.prefix_names[prefixName]);
+    if (config.senders_imsi && prefixName && config.senders_imsi.prefix_names && config.senders_imsi.prefix_names[prefixName]) {
+        imsiSenders = filterOutCandidates(config.senders_imsi.prefix_names[prefixName]);
         if (logger) logger.verbose('MODEM-CHOOSER: Try to use imsi senders by prefix name', { destination, prefixName, imsiSenders });
     }
 
-    if (!imsiSenders.length && config.imsi_senders && config.imsi_senders.unknown_prefix) {
-        imsiSenders = filterOutCandidates(config.imsi_senders.unknown_prefix);
+    if (!imsiSenders.length && config.senders_imsi && config.senders_imsi.unknown_prefix) {
+        imsiSenders = filterOutCandidates(config.senders_imsi.unknown_prefix);
         if (logger) logger.verbose('MODEM-CHOOSER: Try to use senders for unknown prefix', { destination, prefixName, imsiSenders });
     }
 
@@ -48,8 +48,8 @@ exports.chooser = async function chooser(destination, config) {
         if (logger) logger.verbose('MODEM-CHOOSER: Try to use sender by last seen', { destination, prefixName, imsiSenders });
     }
 
-    if (!imsiSenders.length && config.imsi_senders && config.imsi_senders.default) {
-        imsiSenders = filterOutCandidates(config.imsi_senders.default);
+    if (!imsiSenders.length && config.senders_imsi && config.senders_imsi.default) {
+        imsiSenders = filterOutCandidates(config.senders_imsi.default);
         if (logger) logger.verbose('MODEM-CHOOSER: Try to use default senders', { destination, prefixName, imsiSenders });
     }