diff --git a/src/heap/heap.h b/src/heap/heap.h
index 936d0fa919..f247aa38f5 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -238,10 +238,11 @@ class Heap {
 #endif
 
   // Semi-space size needs to be a multiple of page size.
-  static const size_t kMinSemiSpaceSizeInKB =
-      1 * kPointerMultiplier * ((1 << kPageSizeBits) / KB);
-  static const size_t kMaxSemiSpaceSizeInKB =
-      16 * kPointerMultiplier * ((1 << kPageSizeBits) / KB);
+  static const size_t kMinSemiSpaceSizeInKB = 512 * kPointerMultiplier;
+  static const size_t kMaxSemiSpaceSizeInKB = 8192 * kPointerMultiplier;
+
+  STATIC_ASSERT(kMinSemiSpaceSizeInKB* KB % (1 << kPageSizeBits) == 0);
+  STATIC_ASSERT(kMaxSemiSpaceSizeInKB* KB % (1 << kPageSizeBits) == 0);
 
   static const int kTraceRingBufferSize = 512;
   static const int kStacktraceBufferSize = 512;
diff --git a/test/unittests/heap/heap-unittest.cc b/test/unittests/heap/heap-unittest.cc
index 2f588a843e..12bd46886d 100644
--- a/test/unittests/heap/heap-unittest.cc
+++ b/test/unittests/heap/heap-unittest.cc
@@ -20,14 +20,13 @@ typedef TestWithIsolate HeapTest;
 typedef TestWithIsolateAndPointerCompression HeapWithPointerCompressionTest;
 
 TEST(Heap, SemiSpaceSize) {
-  const size_t KB = static_cast<size_t>(i::KB);
   const size_t MB = static_cast<size_t>(i::MB);
   const size_t pm = i::Heap::kPointerMultiplier;
-  ASSERT_EQ(1u * pm * MB / 2, i::Heap::ComputeMaxSemiSpaceSize(0u) * KB);
-  ASSERT_EQ(1u * pm * MB / 2, i::Heap::ComputeMaxSemiSpaceSize(512u * MB) * KB);
-  ASSERT_EQ(2u * pm * MB, i::Heap::ComputeMaxSemiSpaceSize(1024u * MB) * KB);
-  ASSERT_EQ(5u * pm * MB, i::Heap::ComputeMaxSemiSpaceSize(2024u * MB) * KB);
-  ASSERT_EQ(8u * pm * MB, i::Heap::ComputeMaxSemiSpaceSize(4095u * MB) * KB);
+  ASSERT_EQ(512u * pm, i::Heap::ComputeMaxSemiSpaceSize(0u));
+  ASSERT_EQ(512u * pm, i::Heap::ComputeMaxSemiSpaceSize(512u * MB));
+  ASSERT_EQ(2048u * pm, i::Heap::ComputeMaxSemiSpaceSize(1024u * MB));
+  ASSERT_EQ(5120u * pm, i::Heap::ComputeMaxSemiSpaceSize(2024u * MB));
+  ASSERT_EQ(8192u * pm, i::Heap::ComputeMaxSemiSpaceSize(4095u * MB));
 }
 
 TEST_F(HeapTest, ASLR) {