diff --git a/common/modules/mixly-modules/web/serial-transport.js b/common/modules/mixly-modules/web/serial-transport.js
index 6f4d1726..70ea3e11 100644
--- a/common/modules/mixly-modules/web/serial-transport.js
+++ b/common/modules/mixly-modules/web/serial-transport.js
@@ -110,7 +110,11 @@ class Transport {
 
     async setRTS(state) {
         await this.serial.setRTS(state);
-        if (this.tracing) this.trace(`Set RTS = ${state}`);
+        await this.serial.setDTR(this.serial.getDTR());
+        if (this.tracing) {
+            this.trace(`Set RTS = ${state}`);
+            this.trace(`Set DTR = ${this.serial.getDTR()}`);
+        }
     }
 
     async setDTR(state) {
diff --git a/common/modules/mixly-modules/web/serialport.js b/common/modules/mixly-modules/web/serialport.js
index 2b72d2b8..ebadf309 100644
--- a/common/modules/mixly-modules/web/serialport.js
+++ b/common/modules/mixly-modules/web/serialport.js
@@ -224,11 +224,23 @@ class WebSerialPort extends Serial {
     }
 
     async setDTR(dtr) {
-        return this.setDTRAndRTS(dtr, this.getRTS());
+        if (!this.isOpened()) {
+            return;
+        }
+        await this.#serialport_.setSignals({
+            dataTerminalReady: dtr
+        });
+        super.setDTR(dtr);
     }
 
     async setRTS(rts) {
-        return this.setDTRAndRTS(this.getDTR(), rts);
+        if (!this.isOpened()) {
+            return;
+        }
+        await this.#serialport_.setSignals({
+            requestToSend: rts
+        });
+        super.setRTS(rts);
     }
 
     getVID() {