diff --git a/go/src/v.io/mojo/discovery/apptest/apptest_util.go b/go/src/v.io/mojo/discovery/apptest/apptest_util.go
index 5f0cfa1..f7667d2 100644
--- a/go/src/v.io/mojo/discovery/apptest/apptest_util.go
+++ b/go/src/v.io/mojo/discovery/apptest/apptest_util.go
@@ -36,7 +36,7 @@
 }
 
 func scan(d mojom.Discovery, query string) (<-chan mojom.Update_Pointer, func(), error) {
-	ch := make(chan mojom.Update_Pointer)
+	ch := make(chan mojom.Update_Pointer, 10)
 	handler := &mockScanHandler{ch}
 	req, ptr := mojom.CreateMessagePipeForScanHandler()
 	stub := mojom.NewScanHandlerStub(req, handler, bindings.GetAsyncWaiter())
@@ -101,9 +101,11 @@
 		return nil, err
 	}
 	defer func() {
+		go func() {
+			for range scanCh {
+			}
+		}()
 		stop()
-		for range scanCh {
-		}
 	}()
 
 	updatePtrs := make([]mojom.Update_Pointer, 0, expectedUpdates)
diff --git a/mojoapptests b/mojoapptests
index 3d39823..c5351c1 100644
--- a/mojoapptests
+++ b/mojoapptests
@@ -6,15 +6,13 @@
     "test": "https://test.v.io/discovery_apptests.mojo",
     "test-args": [],
     "shell-args": ["--args-for=https://mojo.v.io/discovery.mojo --test-mode"],
-    "timeout": 300,
+    "timeout": 120,
   },
-  # Testing dart apptests timeout failure with a large timeout value.
-  # See https://github.com/vanadium/issues/issues/1278
   {
     "test": "https://dart.test.mojo.v.io/discovery_apptests.dart",
     "type": "dart",
     "dart_strict_mode": True,
     "shell-args": ["--args-for=https://mojo.v.io/discovery.mojo --test-mode"],
-    "timeout": 300,
+    "timeout": 120,
   }
 ]