diff --git a/NEWS b/NEWS
index 21c7d6165d5..f53996ae660 100644
--- a/NEWS
+++ b/NEWS
@@ -32,6 +32,8 @@ PHP                                                                        NEWS
   . Fixed bug GH-11808 (Live filesystem modified by tests). (nielsdos)
   . Fixed GH-13402 (Added validation of `\n` in $additional_headers of mail()).
     (SakiTakamachi)
+  . Fixed bug GH-13203 (file_put_contents fail on strings over 4GB on Windows).
+    (divinity76)
 
 - XML:
   . Fixed bug GH-13517 (Multiple test failures when building with
diff --git a/ext/standard/tests/file/file_put_contents_5gb.phpt b/ext/standard/tests/file/file_put_contents_5gb.phpt
new file mode 100644
index 00000000000..7d91ef691b5
--- /dev/null
+++ b/ext/standard/tests/file/file_put_contents_5gb.phpt
@@ -0,0 +1,67 @@
+--TEST--
+Test file_put_contents() function with 5GB string
+--SKIPIF--
+<?php
+if (PHP_INT_SIZE < 5) {
+    // 4=4gb, 5=549gb, 8=9exabytes
+    skip("skip PHP_INT_SIZE<5 will not fit test string in RAM");
+}
+if (getenv('SKIP_SLOW_TESTS')) {
+    die('skip slow test');
+}
+function get_system_memory(): int|float|false
+{
+    if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
+        // Windows-based memory check
+        @exec('wmic OS get FreePhysicalMemory', $output);
+        if (isset($output[1])) {
+            return ((int)trim($output[1])) * 1024;
+        }
+    } else {
+        // Unix/Linux-based memory check
+        $memInfo = @file_get_contents("/proc/meminfo");
+        if ($memInfo) {
+            preg_match('/MemFree:\s+(\d+) kB/', $memInfo, $matches);
+            return $matches[1] * 1024; // Convert to bytes
+        }
+    }
+    return false;
+}
+if (get_system_memory() < 10 * 1024 * 1024 * 1024) {
+    die('skip Reason: Insufficient RAM (less than 10GB)');
+}
+$tmpfile = sys_get_temp_dir() . DIRECTORY_SEPARATOR . "test_file_put_contents_5gb.bin";
+$tmpfileh = fopen($tmpfile, "wb");
+if ($tmpfileh === false) {
+    die('skip Reason: Unable to create temporary file');
+}
+fclose($tmpfileh);
+unlink($tmpfile);
+if (disk_free_space(dirname($tmpfile)) < 10 * 1024 * 1024 * 1024) {
+    die('skip Reason: Insufficient disk space (less than 10GB)');
+}
+?>
+--INI--
+memory_limit=6G
+--FILE--
+<?php
+$tmpfile = sys_get_temp_dir() . DIRECTORY_SEPARATOR . "test_file_put_contents_5gb.bin";
+$large_string = str_repeat('a', 5 * 1024 * 1024 * 1024);
+$result = file_put_contents($tmpfile, $large_string);
+if ($result !== strlen($large_string)) {
+    echo "Could only write $result bytes of " . strlen($large_string) . " bytes.";
+    var_dump(error_get_last());
+} else {
+    echo "File written successfully.";
+}
+clearstatcache(true, $tmpfile);
+if (file_exists($tmpfile)) {
+    unlink($tmpfile);
+}
+?>
+--CLEAN--
+<?php
+@unlink(sys_get_temp_dir() . DIRECTORY_SEPARATOR . "test_file_put_contents_5gb.bin");
+?>
+--EXPECT--
+File written successfully.
diff --git a/main/streams/plain_wrapper.c b/main/streams/plain_wrapper.c
index e9a30f33340..c77bd1e2415 100644
--- a/main/streams/plain_wrapper.c
+++ b/main/streams/plain_wrapper.c
@@ -40,6 +40,7 @@
 # include "win32/time.h"
 # include "win32/ioutil.h"
 # include "win32/readdir.h"
+# include <limits.h>
 #endif
 
 #define php_stream_fopen_from_fd_int(fd, mode, persistent_id)	_php_stream_fopen_from_fd_int((fd), (mode), (persistent_id) STREAMS_CC)
@@ -353,11 +354,7 @@ static ssize_t php_stdiop_write(php_stream *stream, const char *buf, size_t coun
 
 	if (data->fd >= 0) {
 #ifdef PHP_WIN32
-		ssize_t bytes_written;
-		if (ZEND_SIZE_T_UINT_OVFL(count)) {
-			count = UINT_MAX;
-		}
-		bytes_written = _write(data->fd, buf, (unsigned int)count);
+		ssize_t bytes_written = _write(data->fd, buf, (unsigned int)(count > INT_MAX ? INT_MAX : count));
 #else
 		ssize_t bytes_written = write(data->fd, buf, count);
 #endif