diff --git a/src/station_utils.cpp b/src/station_utils.cpp
index 117d349..d655a8b 100644
--- a/src/station_utils.cpp
+++ b/src/station_utils.cpp
@@ -33,7 +33,7 @@ namespace STATION_Utils {
         lastHeardStation_temp.clear();
     }
 
-    void updateLastHeard(String station) {
+    void updateLastHeard(const String& station) {
         deleteNotHeard();
         bool stationHeard = false;
         for (int i = 0; i < lastHeardStation.size(); i++) {
@@ -53,7 +53,7 @@ namespace STATION_Utils {
         fourthLine += String(lastHeardStation.size());
     }
 
-    bool wasHeard(String station) {
+    bool wasHeard(const String& station) {
         deleteNotHeard();
         for (int i = 0; i < lastHeardStation.size(); i++) {
             if (lastHeardStation[i].substring(0, lastHeardStation[i].indexOf(",")) == station) {
@@ -75,7 +75,7 @@ namespace STATION_Utils {
         }
     }
 
-    bool check25SegBuffer(String station, String textMessage) {
+    bool check25SegBuffer(const String& station, const String& textMessage) {
         if (!packet25SegBuffer.empty()) {
             bool shouldBeIgnored = false;
             for (int i = 0; i < packet25SegBuffer.size(); i++) {
@@ -109,7 +109,7 @@ namespace STATION_Utils {
         }
     }
 
-    void addToOutputPacketBuffer(String packet) {
+    void addToOutputPacketBuffer(const String& packet) {
         outputPacketBuffer.push_back(packet);
     }
 
diff --git a/src/station_utils.h b/src/station_utils.h
index d9423b9..a4228a3 100644
--- a/src/station_utils.h
+++ b/src/station_utils.h
@@ -7,12 +7,12 @@
 namespace STATION_Utils {
 
     void deleteNotHeard();
-    void updateLastHeard(String station);
-    bool wasHeard(String station);
+    void updateLastHeard(const String& station);
+    bool wasHeard(const String& station);
     void clean25SegBuffer();
-    bool check25SegBuffer(String station, String textMessage);
+    bool check25SegBuffer(const String& station, const String& textMessage);
     void processOutputPacketBuffer();
-    void addToOutputPacketBuffer(String packet);
+    void addToOutputPacketBuffer(const String& packet);
 
 }
 
diff --git a/src/tnc_utils.cpp b/src/tnc_utils.cpp
index 4e38dba..23b9d89 100644
--- a/src/tnc_utils.cpp
+++ b/src/tnc_utils.cpp
@@ -105,10 +105,10 @@ namespace TNC_Utils {
         }
     }
 
-    void sendToClients(String packet) {
-        packet = packet.substring(3);
+    void sendToClients(const String& packet) {
+        String cleanPacket = packet.substring(3);
 
-        const String kissEncoded = encodeKISS(packet);
+        const String kissEncoded = encodeKISS(cleanPacket);
 
         for (int i = 0; i < MAX_CLIENTS; i++) {
             auto client = clients[i];
@@ -123,12 +123,12 @@ namespace TNC_Utils {
             }
         }
         Utils::print("---> Sent to TNC       : ");
-        Utils::println(packet);
+        Utils::println(cleanPacket);
     }
 
-    void sendToSerial(String packet) {
-        packet = packet.substring(3);
-        Serial.print(encodeKISS(packet));
+    void sendToSerial(const String& packet) {
+        String cleanPacket = packet.substring(3);
+        Serial.print(encodeKISS(cleanPacket));
         Serial.flush();
     }
 
diff --git a/src/tnc_utils.h b/src/tnc_utils.h
index 3b4b0b2..6e6e004 100644
--- a/src/tnc_utils.h
+++ b/src/tnc_utils.h
@@ -8,8 +8,8 @@ namespace TNC_Utils {
     void setup();
     void loop();
     
-    void sendToClients(String packet);
-    void sendToSerial(String packet);
+    void sendToClients(const String& packet);
+    void sendToSerial(const String& packet);
 
 }