diff --git a/htdocs/lib/DemodulatorPanel.js b/htdocs/lib/DemodulatorPanel.js
index bbaffa52..e10388a2 100644
--- a/htdocs/lib/DemodulatorPanel.js
+++ b/htdocs/lib/DemodulatorPanel.js
@@ -197,9 +197,11 @@ DemodulatorPanel.prototype.collectParams = function() {
 };
 
 DemodulatorPanel.prototype.startDemodulator = function() {
-    if (!Modes.initComplete() || !this.center_freq) return;
     var params = this.collectParams();
-    this._apply(params);
+    this.setMagicKey(params.magic_key);
+
+    if (Modes.initComplete() && this.center_freq)
+        this._apply(params);
 };
 
 DemodulatorPanel.prototype.stopDemodulator = function() {
@@ -212,7 +214,6 @@ DemodulatorPanel.prototype.stopDemodulator = function() {
 }
 
 DemodulatorPanel.prototype._apply = function(params) {
-    this.setMagicKey(params.magic_key);
     if (params.secondary_mod) {
         this.setMode(params.secondary_mod, params.mod)
     } else {
diff --git a/htdocs/openwebrx.js b/htdocs/openwebrx.js
index 25304e48..9c2e27b1 100644
--- a/htdocs/openwebrx.js
+++ b/htdocs/openwebrx.js
@@ -1971,7 +1971,10 @@ function secondary_demod_waterfall_set_zoom(low_cut, high_cut) {
 
 function sdr_profile_changed() {
     var value = $('#openwebrx-sdr-profiles-listbox').val();
-    ws.send(JSON.stringify({type: "selectprofile", params: {profile: value}}));
+    var key = $('#openwebrx-panel-receiver').demodulatorPanel().getMagicKey();
+    ws.send(JSON.stringify({
+        "type": "selectprofile", "params": { "profile": value, "key": key }
+    }));
 }
 
 function tuning_step_changed() {
diff --git a/owrx/config/defaults.py b/owrx/config/defaults.py
index b4b0260f..bc24c3eb 100644
--- a/owrx/config/defaults.py
+++ b/owrx/config/defaults.py
@@ -155,6 +155,7 @@ defaultConfig = PropertyLayer(
     waterfall_levels=PropertyLayer(min=-88, max=-20),
     waterfall_auto_levels=PropertyLayer(min=3, max=10),
     waterfall_auto_min_range=50,
+    key_locked=False,
     ui_opacity=100,
     ui_frame=False,
     ui_swap_wheel=False,
diff --git a/owrx/connection.py b/owrx/connection.py
index 8cbc2cf8..5d6e73c2 100644
--- a/owrx/connection.py
+++ b/owrx/connection.py
@@ -296,10 +296,15 @@ class OpenWebRxReceiverClient(OpenWebRxClient, SdrSourceEventClient):
                     if "params" in message and "sdr" in message["params"]:
                         self.setSdr(message["params"]["sdr"])
                 elif message["type"] == "selectprofile":
+                    # Locked source's profile can only be changed with a key
                     if "params" in message and "profile" in message["params"]:
-                        profile = message["params"]["profile"].split("|")
+                        params  = message["params"]
+                        profile = params["profile"].split("|")
+                        magic   = self.stack["magic_key"]
+                        key     = params["key"] if "key" in params else None
                         self.setSdr(profile[0])
-                        self.sdr.activateProfile(profile[1])
+                        if not self.sdr.isLocked() or magic == "" or key == magic:
+                            self.sdr.activateProfile(profile[1])
                 elif message["type"] == "setfrequency":
                     # If the magic key is set in the settings, only allow
                     # changes if it matches the received key
diff --git a/owrx/sdr.py b/owrx/sdr.py
index d31417b5..79b216a2 100644
--- a/owrx/sdr.py
+++ b/owrx/sdr.py
@@ -233,6 +233,11 @@ class SdrService(object):
         if not sources:
             return None
         # TODO: configure default sdr in config? right now it will pick the first one off the list.
+        # For now, try returning the first unlocked source
+        for src in sources.keys():
+            if not sources[src].isLocked():
+                return sources[src]
+        # If no unlocked sources, just return the first one
         return sources[list(sources.keys())[0]]
 
     @staticmethod
diff --git a/owrx/source/__init__.py b/owrx/source/__init__.py
index 0db26469..c84a0eff 100644
--- a/owrx/source/__init__.py
+++ b/owrx/source/__init__.py
@@ -383,6 +383,9 @@ class SdrSource(ABC):
     def isAvailable(self):
         return self.monitor is not None
 
+    def isLocked(self):
+        return "key_locked" in self.props and self.props["key_locked"]
+
     def stop(self):
         with self.modificationLock:
             if self.process is not None:
@@ -560,12 +563,6 @@ class SdrDeviceDescription(object):
     def getInputs(self) -> List[Input]:
         return [
             CheckboxInput("enabled", "Enable this device", converter=OptionalConverter(defaultFormValue=True)),
-            GainInput("rf_gain", "Device gain", self.hasAgc()),
-            NumberInput(
-                "ppm",
-                "Frequency correction",
-                append="ppm",
-            ),
             CheckboxInput(
                 "always-on",
                 "Keep device running at all times",
@@ -575,6 +572,16 @@ class SdrDeviceDescription(object):
                 "services",
                 "Run background services on this device",
             ),
+            CheckboxInput(
+                "key_locked",
+                "Protect access to this device with a magic key",
+            ),
+            GainInput("rf_gain", "Device gain", self.hasAgc()),
+            NumberInput(
+                "ppm",
+                "Frequency correction",
+                append="ppm",
+            ),
             ExponentialInput(
                 "lfo_offset",
                 "Oscillator offset",
@@ -608,6 +615,7 @@ class SdrDeviceDescription(object):
         keys = [
             "always-on",
             "services",
+            "key_locked",
             "rf_gain",
             "lfo_offset",
             "waterfall_levels",