diff --git a/src/heap.cc b/src/heap.cc
index 868ae48001..f948c6c88f 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -1086,7 +1086,7 @@ void Heap::Scavenge() {
 
   incremental_marking()->PrepareForScavenge();
 
-  AdvanceSweepers(new_space_.Size());
+  AdvanceSweepers(static_cast<int>(new_space_.Size()));
 
   // Flip the semispaces.  After flipping, to space is empty, from space has
   // live objects.
@@ -4559,7 +4559,8 @@ bool Heap::IdleNotification(int hint) {
   intptr_t step_size = size_factor * IncrementalMarking::kAllocatedThreshold;
 
   if (incremental_marking()->IsStopped()) {
-    if (!IsSweepingComplete() && !AdvanceSweepers(step_size)) {
+    if (!IsSweepingComplete() &&
+        !AdvanceSweepers(static_cast<int>(step_size))) {
       return false;
     }
   }
diff --git a/test/cctest/test-heap.cc b/test/cctest/test-heap.cc
index 3daf81991d..71f9ac5b3f 100644
--- a/test/cctest/test-heap.cc
+++ b/test/cctest/test-heap.cc
@@ -1313,7 +1313,7 @@ TEST(IdleNotificationAdvancesIncrementalMarking) {
   }
   intptr_t old_size = HEAP->SizeOfObjects();
   bool no_idle_work = v8::V8::IdleNotification();
-  while (!v8::V8::IdleNotification());
+  while (!v8::V8::IdleNotification()) ;
   intptr_t new_size = HEAP->SizeOfObjects();
   CHECK(no_idle_work || new_size < 3 * old_size / 4);
 }