diff --git a/tdutils/td/utils/crypto.cpp b/tdutils/td/utils/crypto.cpp
index 51dae8377..4671acc00 100644
--- a/tdutils/td/utils/crypto.cpp
+++ b/tdutils/td/utils/crypto.cpp
@@ -860,7 +860,7 @@ static void pbkdf2_impl(Slice password, Slice salt, int iteration_count, Mutable
         LOG(FATAL) << "Failed to HMAC";
       }
       for (int i = 0; i < hash_size; i++) {
-        dest[i] ^= buf[i];
+        dest[i] = static_cast<unsigned char>(dest[i] ^ buf[i]);
       }
     }
   }
diff --git a/tdutils/td/utils/port/MemoryMapping.cpp b/tdutils/td/utils/port/MemoryMapping.cpp
index 8a06aa103..032c0a5f7 100644
--- a/tdutils/td/utils/port/MemoryMapping.cpp
+++ b/tdutils/td/utils/port/MemoryMapping.cpp
@@ -38,10 +38,8 @@ class MemoryMapping::Impl {
   int64 offset_;
 };
 
+#if !TD_WINDOWS
 static Result<int64> get_page_size() {
-#if TD_WINDOWS
-  return Status::Error("Unimplemented");
-#else
   static Result<int64> page_size = []() -> Result<int64> {
     auto page_size = sysconf(_SC_PAGESIZE);
     if (page_size < 0) {
@@ -50,8 +48,8 @@ static Result<int64> get_page_size() {
     return page_size;
   }();
   return page_size.clone();
-#endif
 }
+#endif
 
 Result<MemoryMapping> MemoryMapping::create_anonymous(const MemoryMapping::Options &options) {
   return Status::Error("Unsupported yet");
diff --git a/tdutils/td/utils/port/uname.cpp b/tdutils/td/utils/port/uname.cpp
index 5f3caf17c..6eea32bed 100644
--- a/tdutils/td/utils/port/uname.cpp
+++ b/tdutils/td/utils/port/uname.cpp
@@ -230,7 +230,7 @@ Slice get_operating_system_version() {
 #if WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP | WINAPI_PARTITION_SYSTEM)
     auto handle = GetModuleHandle(L"ntdll.dll");
     if (handle != nullptr) {
-      using RtlGetVersionPtr = LONG(WINAPI *)(PRTL_OSVERSIONINFOEXW);
+      using RtlGetVersionPtr = LONG(WINAPI *)(_Out_ PRTL_OSVERSIONINFOEXW);
       RtlGetVersionPtr RtlGetVersion = reinterpret_cast<RtlGetVersionPtr>(GetProcAddress(handle, "RtlGetVersion"));
       if (RtlGetVersion != nullptr) {
         RTL_OSVERSIONINFOEXW os_version_info = {};
@@ -240,7 +240,7 @@ Slice get_operating_system_version() {
           auto minor = os_version_info.dwMinorVersion;
           bool is_server = os_version_info.wProductType != VER_NT_WORKSTATION;
 
-          if (major == 10 && minor >= 0) {
+          if (major == 10) {
             if (is_server) {
               return os_version_info.dwBuildNumber >= 17623 ? "Windows Server 2019" : "Windows Server 2016";
             }