diff --git a/port/win/env_win.cc b/port/win/env_win.cc
index 1b97f756a..0b51d72f0 100644
--- a/port/win/env_win.cc
+++ b/port/win/env_win.cc
@@ -1088,19 +1088,14 @@ std::string Env::GenerateUniqueId() {
   UuidCreateSequential(&uuid);
 
   RPC_CSTR rpc_str;
-#ifndef NDEBUG
-  assert(UuidToStringA(&uuid, &rpc_str) == RPC_S_OK);
-#else
-  UuidToStringA(&uuid, &rpc_str);
-#endif
+  auto status = UuidToStringA(&uuid, &rpc_str);
+  (void)status;
+  assert(status == RPC_S_OK);
 
   result = reinterpret_cast<char*>(rpc_str);
 
-#ifndef NDEBUG
-  assert(RpcStringFreeA(&rpc_str) == RPC_S_OK);
-#else
-  RpcStringFreeA(&rpc_str);
-#endif
+  status = RpcStringFreeA(&rpc_str);
+  assert(status == RPC_S_OK);
 
   return result;
 }
diff --git a/port/win/io_win.cc b/port/win/io_win.cc
index 0b0eccfce..bf5d18327 100644
--- a/port/win/io_win.cc
+++ b/port/win/io_win.cc
@@ -32,7 +32,7 @@ bool IsPowerOfTwo(const size_t alignment) {
 }
 
 inline
-bool IsSectorAligned(const size_t off) {
+bool IsSectorAligned(const size_t off) { 
   return (off & (kSectorSize - 1)) == 0;
 }
 
@@ -194,13 +194,12 @@ WinMmapReadableFile::WinMmapReadableFile(const std::string& fileName,
       length_(length) {}
 
 WinMmapReadableFile::~WinMmapReadableFile() {
-#ifndef NDEBUG
-  assert(::UnmapViewOfFile(mapped_region_));
-  assert(::CloseHandle(hMap_));
-#else
-  ::UnmapViewOfFile(mapped_region_);
-  ::CloseHandle(hMap_);
-#endif
+  BOOL ret = ::UnmapViewOfFile(mapped_region_);
+  (void)ret;
+  assert(ret);
+
+  ret = ::CloseHandle(hMap_);
+  assert(ret);
 }
 
 Status WinMmapReadableFile::Read(uint64_t offset, size_t n, Slice* result,
@@ -747,9 +746,8 @@ Status WinWritableImpl::AppendImpl(const Slice& data) {
 
   assert(data.size() < std::numeric_limits<DWORD>::max());
 
-#ifndef NDEBUG
   uint64_t written = 0;
-#endif
+  (void)written;
 
   if (file_data_->use_direct_io()) {
 
@@ -769,9 +767,7 @@ Status WinWritableImpl::AppendImpl(const Slice& data) {
         "Failed to pwrite for: " + file_data_->GetName(), lastError);
     }
     else {
-#ifndef NDEBUG
       written = ret;
-#endif
     }
 
   } else {
@@ -785,9 +781,7 @@ Status WinWritableImpl::AppendImpl(const Slice& data) {
         lastError);
     }
     else {
-#ifndef NDEBUG
       written = bytesWritten;
-#endif
     }
   }