diff --git a/devtools/client/debugger/panel.js b/devtools/client/debugger/panel.js
index e9c2634baa0b..24da5a1aef3a 100644
--- a/devtools/client/debugger/panel.js
+++ b/devtools/client/debugger/panel.js
@@ -77,12 +77,6 @@ class DebuggerPanel {
 
     registerStoreObserver(this._store, this._onDebuggerStateChange.bind(this));
 
-    const resourceWatcher = this.toolbox.resourceWatcher;
-    await resourceWatcher.watchResources(
-      [resourceWatcher.TYPES.ERROR_MESSAGE],
-      { onAvailable: actions.addExceptionFromResources }
-    );
-
     return this;
   }
 
@@ -273,11 +267,6 @@ class DebuggerPanel {
   }
 
   destroy() {
-    const resourceWatcher = this.toolbox.resourceWatcher;
-    resourceWatcher.unwatchResources([resourceWatcher.TYPES.ERROR_MESSAGE], {
-      onAvailable: this._actions.addExceptionFromResources,
-    });
-
     this.panelWin.Debugger.destroy();
     this.emit("destroyed");
   }
diff --git a/devtools/client/debugger/src/client/firefox.js b/devtools/client/debugger/src/client/firefox.js
index ce05aacac009..37f246d172c1 100644
--- a/devtools/client/debugger/src/client/firefox.js
+++ b/devtools/client/debugger/src/client/firefox.js
@@ -57,6 +57,9 @@ export async function onConnect(
   await resourceWatcher.watchResources([resourceWatcher.TYPES.THREAD_STATE], {
     onAvailable: onBreakpointAvailable,
   });
+  await resourceWatcher.watchResources([resourceWatcher.TYPES.ERROR_MESSAGE], {
+    onAvailable: actions.addExceptionFromResources,
+  });
 }
 
 export function onDisconnect() {
@@ -71,6 +74,9 @@ export function onDisconnect() {
   resourceWatcher.unwatchResources([resourceWatcher.TYPES.THREAD_STATE], {
     onAvailable: onBreakpointAvailable,
   });
+  resourceWatcher.unwatchResources([resourceWatcher.TYPES.ERROR_MESSAGE], {
+    onAvailable: actions.addExceptionFromResources,
+  });
   sourceQueue.clear();
 }