diff --git a/src/platform-linux.cc b/src/platform-linux.cc
index 2d6160e473..855ebf78e1 100644
--- a/src/platform-linux.cc
+++ b/src/platform-linux.cc
@@ -477,7 +477,7 @@ OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
 
 
 PosixMemoryMappedFile::~PosixMemoryMappedFile() {
-  if (memory_) munmap(memory_, size_);
+  if (memory_) OS::Free(memory_, size_);
   fclose(file_);
 }
 
@@ -559,7 +559,7 @@ void OS::SignalCodeMovingGC() {
   void* addr = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_PRIVATE,
                     fileno(f), 0);
   ASSERT(addr != MAP_FAILED);
-  munmap(addr, size);
+  OS::Free(addr, size);
   fclose(f);
 }
 
@@ -621,21 +621,31 @@ VirtualMemory::VirtualMemory(size_t size, size_t alignment)
                            kMmapFd,
                            kMmapFdOffset);
   if (reservation == MAP_FAILED) return;
+
   Address base = static_cast<Address>(reservation);
   Address aligned_base = RoundUp(base, alignment);
-  ASSERT(base <= aligned_base);
+  ASSERT_LE(base, aligned_base);
 
   // Unmap extra memory reserved before and after the desired block.
-  size_t bytes_prior = static_cast<size_t>(aligned_base - base);
-  if (bytes_prior > 0) {
-    munmap(base, bytes_prior);
-  }
-  if (static_cast<size_t>(aligned_base - base) < request_size - size) {
-    munmap(aligned_base + size, request_size - size - bytes_prior);
+  if (aligned_base != base) {
+    size_t prefix_size = static_cast<size_t>(aligned_base - base);
+    OS::Free(base, prefix_size);
+    request_size -= prefix_size;
   }
 
+  size_t aligned_size = RoundUp(size, OS::AllocateAlignment());
+  ASSERT_LE(aligned_size, request_size);
+
+  if (aligned_size != request_size) {
+    size_t suffix_size = request_size - aligned_size;
+    OS::Free(aligned_base + aligned_size, suffix_size);
+    request_size -= suffix_size;
+  }
+
+  ASSERT(aligned_size == request_size);
+
   address_ = static_cast<void*>(aligned_base);
-  size_ = size;
+  size_ = aligned_size;
 }
 
 
diff --git a/src/platform-macos.cc b/src/platform-macos.cc
index 0ac8fbe2d7..a70b43c027 100644
--- a/src/platform-macos.cc
+++ b/src/platform-macos.cc
@@ -228,7 +228,7 @@ OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
 
 
 PosixMemoryMappedFile::~PosixMemoryMappedFile() {
-  if (memory_) munmap(memory_, size_);
+  if (memory_) OS::Free(memory_, size_);
   fclose(file_);
 }
 
@@ -353,21 +353,31 @@ VirtualMemory::VirtualMemory(size_t size, size_t alignment)
                            kMmapFd,
                            kMmapFdOffset);
   if (reservation == MAP_FAILED) return;
+
   Address base = static_cast<Address>(reservation);
   Address aligned_base = RoundUp(base, alignment);
-  ASSERT(base <= aligned_base);
+  ASSERT_LE(base, aligned_base);
 
   // Unmap extra memory reserved before and after the desired block.
-  size_t bytes_prior = static_cast<size_t>(aligned_base - base);
-  if (bytes_prior > 0) {
-    munmap(base, bytes_prior);
-  }
-  if (static_cast<size_t>(aligned_base - base) < request_size - size) {
-    munmap(aligned_base + size, request_size - size - bytes_prior);
+  if (aligned_base != base) {
+    size_t prefix_size = static_cast<size_t>(aligned_base - base);
+    OS::Free(base, prefix_size);
+    request_size -= prefix_size;
   }
 
+  size_t aligned_size = RoundUp(size, OS::AllocateAlignment());
+  ASSERT_LE(aligned_size, request_size);
+
+  if (aligned_size != request_size) {
+    size_t suffix_size = request_size - aligned_size;
+    OS::Free(aligned_base + aligned_size, suffix_size);
+    request_size -= suffix_size;
+  }
+
+  ASSERT(aligned_size == request_size);
+
   address_ = static_cast<void*>(aligned_base);
-  size_ = size;
+  size_ = aligned_size;
 }
 
 
diff --git a/src/platform-openbsd.cc b/src/platform-openbsd.cc
index 973329b9b1..3151d18053 100644
--- a/src/platform-openbsd.cc
+++ b/src/platform-openbsd.cc
@@ -245,7 +245,7 @@ OS::MemoryMappedFile* OS::MemoryMappedFile::create(const char* name, int size,
 
 
 PosixMemoryMappedFile::~PosixMemoryMappedFile() {
-  if (memory_) munmap(memory_, size_);
+  if (memory_) OS::Free(memory_, size_);
   fclose(file_);
 }
 
@@ -342,7 +342,8 @@ VirtualMemory::VirtualMemory(size_t size) {
 
 VirtualMemory::~VirtualMemory() {
   if (IsReserved()) {
-    if (0 == munmap(address(), size())) address_ = MAP_FAILED;
+    OS::Free(address(), size());
+    address_ = MAP_FAILED
   }
 }
 
diff --git a/src/platform-win32.cc b/src/platform-win32.cc
index 46af4dcdcd..8771c43679 100644
--- a/src/platform-win32.cc
+++ b/src/platform-win32.cc
@@ -1413,7 +1413,9 @@ VirtualMemory::VirtualMemory(size_t size, size_t alignment)
   if (address == NULL) return;
   Address base = RoundUp(static_cast<Address>(address), alignment);
   // Try reducing the size by freeing and then reallocating a specific area.
-  ReleaseRegion(address, request_size);
+  bool result = ReleaseRegion(address, request_size);
+  USE(result);
+  ASSERT(result);
   address = VirtualAlloc(base, size, MEM_RESERVE, PAGE_NOACCESS);
   if (address != NULL) {
     request_size = size;
diff --git a/src/platform.h b/src/platform.h
index 85901240f3..99deb1bef0 100644
--- a/src/platform.h
+++ b/src/platform.h
@@ -351,12 +351,14 @@ class VirtualMemory {
 
   void Release() {
     ASSERT(IsReserved());
-    // Notice: Order is somportant here. The VirtualMemory object might live
+    // Notice: Order is important here. The VirtualMemory object might live
     // inside the allocated region.
     void* address = address_;
     size_t size = size_;
     Reset();
-    ReleaseRegion(address, size);
+    bool result = ReleaseRegion(address, size);
+    USE(result);
+    ASSERT(result);
   }
 
   // Assign control of the reserved region to a different VirtualMemory object.
diff --git a/src/spaces.cc b/src/spaces.cc
index 9ae2e625d0..0dc417d791 100644
--- a/src/spaces.cc
+++ b/src/spaces.cc
@@ -341,7 +341,9 @@ void MemoryAllocator::FreeMemory(Address base,
     isolate_->code_range()->FreeRawMemory(base, size);
   } else {
     ASSERT(executable == NOT_EXECUTABLE || !isolate_->code_range()->exists());
-    VirtualMemory::ReleaseRegion(base, size);
+    bool result = VirtualMemory::ReleaseRegion(base, size);
+    USE(result);
+    ASSERT(result);
   }
 }
 
diff --git a/test/mjsunit/mjsunit.status b/test/mjsunit/mjsunit.status
index 966fe0a7e7..941e0e8cc5 100644
--- a/test/mjsunit/mjsunit.status
+++ b/test/mjsunit/mjsunit.status
@@ -35,8 +35,6 @@ bugs: FAIL
 regress/regress-1119: FAIL
 
 ##############################################################################
-# NewGC: http://code.google.com/p/v8/issues/detail?id=1701
-array-join: SKIP
 
 # NewGC: BUG(1719) slow to collect arrays over several contexts.
 regress/regress-524: SKIP