--- a/toolkit/devtools/server/tests/unit/test_sourcemaps-02.js
+++ b/toolkit/devtools/server/tests/unit/test_sourcemaps-02.js
@@ -30,42 +30,38 @@ function test_simple_source_map()
   // Because we are source mapping, we should be notified of a.js, b.js, and
   // c.js as sources, and shouldn"t receive abc.js or test_sourcemaps-01.js.
   let expectedSources = new Set(["http://example.com/www/js/a.js",
                                  "http://example.com/www/js/b.js",
                                  "http://example.com/www/js/c.js"]);
 
   let numNewSources = 0;
 
-  gClient.addListener("newSource", function _onNewSource(aEvent, aPacket) {
-    if (++numNewSources !== 3) {
-      return;
-    }
-    gClient.removeListener("newSource", _onNewSource);
-
+  gClient.addOneTimeListener("paused", function (aEvent, aPacket) {
     gThreadClient.getSources(function (aResponse) {
       do_check_true(!aResponse.error, "Should not get an error");
 
       for (let s of aResponse.sources) {
-        do_check_true(expectedSources.has(s.url),
-                      "The source's url should be one of our original sources");
+        do_check_neq(s.url, "http://example.com/www/js/abc.js",
+                     "Shouldn't get the generated source's url.")
         expectedSources.delete(s.url);
       }
 
       do_check_eq(expectedSources.size, 0,
-                  "Shouldn't be expecting any more sources");
+                  "Should have found all the expected sources sources by now.");
 
       finishClient(gClient);
     });
   });
 
   let { code, map } = (new SourceNode(null, null, null, [
     new SourceNode(1, 0, "a.js", "function a() { return 'a'; }\n"),
     new SourceNode(1, 0, "b.js", "function b() { return 'b'; }\n"),
     new SourceNode(1, 0, "c.js", "function c() { return 'c'; }\n"),
+    "debugger;\n"
   ])).toStringWithSourceMap({
     file: "abc.js",
     sourceRoot: "http://example.com/www/js/"
   });
 
   code += "//@ sourceMappingURL=data:text/json;base64," + btoa(map.toString());
 
   Components.utils.evalInSandbox(code, gDebuggee, "1.8",