diff --git a/devtools/client/debugger/test/mochitest/browser_dbg-navigation.js b/devtools/client/debugger/test/mochitest/browser_dbg-navigation.js
index b8439669b897..8270c9a7e142 100644
--- a/devtools/client/debugger/test/mochitest/browser_dbg-navigation.js
+++ b/devtools/client/debugger/test/mochitest/browser_dbg-navigation.js
@@ -28,6 +28,7 @@ add_task(async function() {
   invokeInTab("firstCall");
   await waitForPaused(dbg);
 
+  await waitForRequestsToSettle(dbg);
   await navigate(dbg, "doc-scripts.html", "simple1.js");
   await selectSource(dbg, "simple1");
   await addBreakpoint(dbg, "simple1.js", 4);
@@ -39,18 +40,29 @@ add_task(async function() {
   assertPausedLocation(dbg);
   is(countSources(dbg), 5, "5 sources are loaded.");
 
+  await waitForRequestsToSettle(dbg);
+  // this test is intermittent without this
+  let onBreakpoint = waitForDispatch(dbg, "SET_BREAKPOINT");
   await navigate(dbg, "doc-scripts.html", ...sources);
+  await onBreakpoint
   is(countSources(dbg), 5, "5 sources are loaded.");
   ok(!getIsPaused(getCurrentThread()), "Is not paused");
 
+  await waitForRequestsToSettle(dbg);
+  // this test is intermittent without this
+  onBreakpoint = waitForDispatch(dbg, "SET_BREAKPOINT");
   await navigate(dbg, "doc-scripts.html", ...sources);
+  await onBreakpoint
   is(countSources(dbg), 5, "5 sources are loaded.");
 
   // Test that the current select source persists across reloads
   await selectSource(dbg, "long.js");
-  await waitForRequestsToSettle(dbg);
 
+  await waitForRequestsToSettle(dbg);
+  // this test is intermittent without this
+  onBreakpoint = waitForDispatch(dbg, "SET_BREAKPOINT");
   await reload(dbg, "long.js");
+  await onBreakpoint
   await waitForSelectedSource(dbg, "long.js");
 
   await waitForRequestsToSettle(dbg);
diff --git a/devtools/shared/client/thread-client.js b/devtools/shared/client/thread-client.js
index 5c8aca6a75b1..864cd06dec04 100644
--- a/devtools/shared/client/thread-client.js
+++ b/devtools/shared/client/thread-client.js
@@ -195,8 +195,15 @@ class ThreadClient extends FrontClassWithSpec(threadSpec) {
   /**
    * Request the loaded sources for the current thread.
    */
-  getSources() {
-    return super.sources();
+  async getSources() {
+    let sources = [];
+    try {
+      ({sources} = await super.sources());
+    } catch (e) {
+      // we may have closed the connection
+      console.log(`getSources failed. Connection may have closed: ${e}`);
+    }
+    return { sources };
   }
 
   /**