diff --git a/src/connection_win.cpp b/src/connection_win.cpp
index 3159c7e..fa80570 100644
--- a/src/connection_win.cpp
+++ b/src/connection_win.cpp
@@ -5,6 +5,7 @@
 #define NOSERVICE
 #define NOIME
 #include <windows.h>
+#include <assert.h>
 
 int GetProcessId()
 {
@@ -75,22 +76,44 @@ bool BaseConnection::Write(const void* data, size_t length)
         return true;
     }
     auto self = reinterpret_cast<BaseConnectionWin*>(this);
+    assert(self);
+    if (!self) {
+        return false;
+    }
     if (self->pipe == INVALID_HANDLE_VALUE) {
         return false;
     }
-    return ::WriteFile(self->pipe, data, (DWORD)length, nullptr, nullptr) == TRUE;
+    assert(data);
+    if (!data) {
+        return false;
+    }
+    const DWORD bytesLength = (DWORD)length;
+    DWORD bytesWritten = 0;
+    return ::WriteFile(self->pipe, data, bytesLength, &bytesWritten, nullptr) == TRUE &&
+      bytesWritten == bytesLength;
 }
 
 bool BaseConnection::Read(void* data, size_t length)
 {
+    assert(data);
+    if (!data) {
+        return false;
+    }
     auto self = reinterpret_cast<BaseConnectionWin*>(this);
+    assert(self);
+    if (!self) {
+        return false;
+    }
     if (self->pipe == INVALID_HANDLE_VALUE) {
         return false;
     }
     DWORD bytesAvailable = 0;
     if (::PeekNamedPipe(self->pipe, nullptr, 0, nullptr, &bytesAvailable, nullptr)) {
         if (bytesAvailable >= length) {
-            if (::ReadFile(self->pipe, data, (DWORD)length, nullptr, nullptr) == TRUE) {
+            DWORD bytesToRead = (DWORD)length;
+            DWORD bytesRead = 0;
+            if (::ReadFile(self->pipe, data, bytesToRead, &bytesRead, nullptr) == TRUE) {
+                assert(bytesToRead == bytesRead);
                 return true;
             }
             else {
@@ -102,4 +125,4 @@ bool BaseConnection::Read(void* data, size_t length)
         Close();
     }
     return false;
-}
+}
\ No newline at end of file