Index: src/OFStdIOStream_Win32Console.m
==================================================================
--- src/OFStdIOStream_Win32Console.m
+++ src/OFStdIOStream_Win32Console.m
@@ -106,18 +106,22 @@
 	void *pool = objc_autoreleasePoolPush();
 	char *buffer = buffer_;
 	of_char16_t *UTF16;
 	size_t j = 0;
 
+	if (length > sizeof(UINT32_MAX))
+		@throw [OFOutOfRangeException exception];
+
 	UTF16 = [self allocMemoryWithSize: sizeof(of_char16_t)
 				    count: length];
 	@try {
 		DWORD UTF16Len;
 		OFDataArray *rest = nil;
 		size_t i = 0;
 
-		if (!ReadConsoleW(_handle, UTF16, length, &UTF16Len, NULL))
+		if (!ReadConsoleW(_handle, UTF16, (DWORD)length, &UTF16Len,
+		    NULL))
 			@throw [OFReadFailedException
 			    exceptionWithObject: self
 				requestedLength: length * 2];
 
 		if (UTF16Len > 0 && _incompleteUTF16Surrogate != 0) {
@@ -224,12 +228,12 @@
 
 	if (_incompleteUTF8SurrogateLen > 0) {
 		of_unichar_t c;
 		of_char16_t UTF16[2];
 		ssize_t UTF8Len;
-		size_t toCopy, UTF16Len;
-		DWORD written;
+		size_t toCopy;
+		DWORD UTF16Len, written;
 
 		UTF8Len = -of_string_utf8_decode(
 		    _incompleteUTF8Surrogate, _incompleteUTF8SurrogateLen, &c);
 
 		OF_ENSURE(UTF8Len > 0);
@@ -311,15 +315,18 @@
 				tmp[j++] = c;
 
 			i += UTF8Len;
 		}
 
-		if (!WriteConsoleW(_handle, tmp, j, &written, NULL) ||
+		if (j > UINT32_MAX)
+			@throw [OFOutOfRangeException exception];
+
+		if (!WriteConsoleW(_handle, tmp, (DWORD)j, &written, NULL) ||
 		    written != j)
 			@throw [OFWriteFailedException
 			    exceptionWithObject: self
 				requestedLength: j * 2];
 	} @finally {
 		[self freeMemory: tmp];
 	}
 }
 @end