diff --git a/devtools/client/framework/toolbox.js b/devtools/client/framework/toolbox.js
index 0af98b8a5a43..b77b0d761f82 100644
--- a/devtools/client/framework/toolbox.js
+++ b/devtools/client/framework/toolbox.js
@@ -3576,11 +3576,11 @@ Toolbox.prototype = {
         settleAll(outstanding)
           .catch(console.error)
           .then(() => {
-            const api = this._netMonitorAPI;
-            this._netMonitorAPI = null;
-            return api ? api.destroy() : null;
-          }, console.error)
-          .then(() => {
+            if (this._netMonitorAPI) {
+              this._netMonitorAPI.destroy();
+              this._netMonitorAPI = null;
+            }
+
             this._removeWindowListeners();
             this._removeChromeEventHandlerEvents();
 
diff --git a/devtools/client/netmonitor/panel.js b/devtools/client/netmonitor/panel.js
index 423f113e2043..494d852d3c4f 100644
--- a/devtools/client/netmonitor/panel.js
+++ b/devtools/client/netmonitor/panel.js
@@ -29,10 +29,9 @@ NetMonitorPanel.prototype = {
     return this;
   },
 
-  async destroy() {
-    await this.panelWin.Netmonitor.destroy();
+  destroy() {
+    this.panelWin.Netmonitor.destroy();
     this.emit("destroyed");
-    return this;
   },
 };
 
diff --git a/devtools/client/netmonitor/src/api.js b/devtools/client/netmonitor/src/api.js
index d5d62b146af3..306b1532ecc4 100644
--- a/devtools/client/netmonitor/src/api.js
+++ b/devtools/client/netmonitor/src/api.js
@@ -80,13 +80,13 @@ NetMonitorAPI.prototype = {
   /**
    * Clean up (unmount from DOM, remove listeners, disconnect).
    */
-  async destroy() {
+  destroy() {
     this.off(EVENTS.PAYLOAD_READY, this.onPayloadReady);
 
-    await this.connector.disconnect();
+    this.connector.disconnect();
 
     if (this.harExportConnector) {
-      await this.harExportConnector.disconnect();
+      this.harExportConnector.disconnect();
     }
   },
 
diff --git a/devtools/client/netmonitor/src/app.js b/devtools/client/netmonitor/src/app.js
index 97d2a4d9b610..c2d8eebfb670 100644
--- a/devtools/client/netmonitor/src/app.js
+++ b/devtools/client/netmonitor/src/app.js
@@ -68,14 +68,14 @@ NetMonitorApp.prototype = {
   /**
    * Clean up (unmount from DOM, remove listeners, disconnect).
    */
-  async destroy() {
+  destroy() {
     unmountComponentAtNode(this.mount);
 
     // Make sure to destroy the API object. It's usually destroyed
     // in the Toolbox destroy method, but we need it here for case
     // where the Network panel is initialized without the toolbox
     // and running in a tab (see initialize.js for details).
-    await this.api.destroy();
+    this.api.destroy();
   },
 
   /**
diff --git a/devtools/client/netmonitor/src/connector/chrome-connector.js b/devtools/client/netmonitor/src/connector/chrome-connector.js
index afa78046b1a9..e2f7e71c2455 100644
--- a/devtools/client/netmonitor/src/connector/chrome-connector.js
+++ b/devtools/client/netmonitor/src/connector/chrome-connector.js
@@ -37,7 +37,7 @@ class ChromeConnector {
     this.connector.willNavigate(this.willNavigate);
   }
 
-  async disconnect() {
+  disconnect() {
     this.connector.disconnect();
   }
 
diff --git a/devtools/client/netmonitor/src/connector/firefox-connector.js b/devtools/client/netmonitor/src/connector/firefox-connector.js
index 67102de6eca3..208d67a31940 100644
--- a/devtools/client/netmonitor/src/connector/firefox-connector.js
+++ b/devtools/client/netmonitor/src/connector/firefox-connector.js
@@ -88,12 +88,12 @@ class FirefoxConnector {
     }
   }
 
-  async disconnect() {
+  disconnect() {
     if (this.actions) {
       this.actions.batchReset();
     }
 
-    await this.removeListeners();
+    this.removeListeners();
 
     if (this.emulationFront) {
       this.emulationFront.destroy();
@@ -162,7 +162,7 @@ class FirefoxConnector {
     await this.webConsoleClient.startListeners(["DocumentEvents"]);
   }
 
-  async removeListeners() {
+  removeListeners() {
     if (this.tabTarget) {
       this.tabTarget.off("close", this.disconnect);
       if (this.webSocketFront) {