diff --git a/config/ext.json b/config/ext.json
index b52076c2..fe75c790 100644
--- a/config/ext.json
+++ b/config/ext.json
@@ -190,7 +190,10 @@
     "parallel": {
         "type": "external",
         "source": "parallel",
-        "arg-type-windows": "with"
+        "arg-type-windows": "with",
+        "lib-depends-windows": [
+            "pthreads4w"
+        ]
     },
     "ldap": {
         "type": "builtin",
diff --git a/config/lib.json b/config/lib.json
index b7a92d04..82f4cf91 100644
--- a/config/lib.json
+++ b/config/lib.json
@@ -125,6 +125,12 @@
             "gmp.h"
         ]
     },
+    "pthreads4w": {
+        "source": "pthreads4w",
+        "static-libs-windows": [
+            "libpthreadVC3.lib"
+        ]
+    },
     "icu": {
         "source": "icu",
         "cpp-library": true,
diff --git a/config/source.json b/config/source.json
index 595389bc..d704d3f6 100644
--- a/config/source.json
+++ b/config/source.json
@@ -52,6 +52,15 @@
             "path": "COPYING"
         }
     },
+    "pthreads4w": {
+        "type": "git",
+        "rev": "master",
+        "url": "https://git.code.sf.net/p/pthreads4w/code",
+        "license": {
+            "type": "file",
+            "path": "LICENSE"
+        }
+    },
     "ext-ds": {
         "type": "url",
         "url": "https://pecl.php.net/get/ds",
diff --git a/src/SPC/builder/windows/library/pthreads4w.php b/src/SPC/builder/windows/library/pthreads4w.php
new file mode 100644
index 00000000..66707cbb
--- /dev/null
+++ b/src/SPC/builder/windows/library/pthreads4w.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SPC\builder\windows\library;
+
+class pthreads4w extends WindowsLibraryBase
+{
+    public const NAME = 'pthreads4w';
+
+    protected function build(): void
+    {
+        cmd()->cd($this->source_dir)
+            ->execWithWrapper(
+                $this->builder->makeSimpleWrapper(
+                    'nmake /E /nologo /f Makefile ' .
+                    'DESTROOT=' . BUILD_ROOT_PATH . ' ' .
+                    'XCFLAGS="/MT" ' . // no dll
+                    'EHFLAGS="/I. /DHAVE_CONFIG_H /Os /Ob2 /D__PTW32_STATIC_LIB /D__PTW32_BUILD_INLINED"'
+                ),
+                'pthreadVC3.inlined_static_stamp'
+            );
+        copy($this->source_dir . '\libpthreadVC3.lib', BUILD_LIB_PATH . '\libpthreadVC3.lib');
+        copy($this->source_dir . '\_ptw32.h', BUILD_INCLUDE_PATH . '\_ptw32.h');
+        copy($this->source_dir . '\pthread.h', BUILD_INCLUDE_PATH . '\pthread.h');
+        copy($this->source_dir . '\sched.h', BUILD_INCLUDE_PATH . '\sched.h');
+        copy($this->source_dir . '\semaphore.h', BUILD_INCLUDE_PATH . '\semaphore.h');
+    }
+}