diff --git a/Misc/NEWS.d/next/Library/2020-05-18-15-38-25.bpo-25920.PxrLY8.rst b/Misc/NEWS.d/next/Library/2020-05-18-15-38-25.bpo-25920.PxrLY8.rst
new file mode 100644
index 0000000..cc60e97
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-05-18-15-38-25.bpo-25920.PxrLY8.rst
@@ -0,0 +1,7 @@
+On macOS, when building Python for macOS 10.4 and older, which wasn't the case
+for python.org macOS installer, :func:`socket.getaddrinfo` no longer uses an
+internal lock to prevent race conditions when calling ``getaddrinfo()`` which
+is thread-safe since macOS 10.5. Python 3.9 requires macOS 10.6 or newer. The
+internal lock caused random hang on fork when another thread was calling
+:func:`socket.getaddrinfo`. The lock was also used on FreeBSD older than 5.3,
+OpenBSD older than 201311 and NetBSD older than 4.
diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c
index 92c246e..f60a27e 100644
--- a/Modules/socketmodule.c
+++ b/Modules/socketmodule.c
@@ -197,43 +197,6 @@
 # define USE_GETHOSTBYNAME_LOCK
 #endif
 
-/* To use __FreeBSD_version, __OpenBSD__, and __NetBSD_Version__ */
-#ifdef HAVE_SYS_PARAM_H
-#include <sys/param.h>
-#endif
-/* On systems on which getaddrinfo() is believed to not be thread-safe,
-   (this includes the getaddrinfo emulation) protect access with a lock.
-
-   getaddrinfo is thread-safe on Mac OS X 10.5 and later. Originally it was
-   a mix of code including an unsafe implementation from an old BSD's
-   libresolv. In 10.5 Apple reimplemented it as a safe IPC call to the
-   mDNSResponder process. 10.5 is the first be UNIX '03 certified, which
-   includes the requirement that getaddrinfo be thread-safe. See issue #25924.
-
-   It's thread-safe in OpenBSD starting with 5.4, released Nov 2013:
-   http://www.openbsd.org/plus54.html
-
-   It's thread-safe in NetBSD starting with 4.0, released Dec 2007:
-
-http://cvsweb.netbsd.org/bsdweb.cgi/src/lib/libc/net/getaddrinfo.c.diff?r1=1.82&r2=1.83
- */
-#if ((defined(__APPLE__) && \
-        MAC_OS_X_VERSION_MIN_REQUIRED < MAC_OS_X_VERSION_10_5) || \
-    (defined(__FreeBSD__) && __FreeBSD_version+0 < 503000) || \
-    (defined(__OpenBSD__) && OpenBSD+0 < 201311) || \
-    (defined(__NetBSD__) && __NetBSD_Version__+0 < 400000000) || \
-    !defined(HAVE_GETADDRINFO))
-#define USE_GETADDRINFO_LOCK
-#endif
-
-#ifdef USE_GETADDRINFO_LOCK
-#define ACQUIRE_GETADDRINFO_LOCK PyThread_acquire_lock(netdb_lock, 1);
-#define RELEASE_GETADDRINFO_LOCK PyThread_release_lock(netdb_lock);
-#else
-#define ACQUIRE_GETADDRINFO_LOCK
-#define RELEASE_GETADDRINFO_LOCK
-#endif
-
 #if defined(__APPLE__) || defined(__CYGWIN__) || defined(__NetBSD__)
 #  include <sys/ioctl.h>
 #endif
@@ -1061,7 +1024,7 @@
 
 /* Lock to allow python interpreter to continue, but only allow one
    thread to be in gethostbyname or getaddrinfo */
-#if defined(USE_GETHOSTBYNAME_LOCK) || defined(USE_GETADDRINFO_LOCK)
+#if defined(USE_GETHOSTBYNAME_LOCK)
 static PyThread_type_lock netdb_lock;
 #endif
 
@@ -1086,14 +1049,12 @@
         hints.ai_socktype = SOCK_DGRAM;         /*dummy*/
         hints.ai_flags = AI_PASSIVE;
         Py_BEGIN_ALLOW_THREADS
-        ACQUIRE_GETADDRINFO_LOCK
         error = getaddrinfo(NULL, "0", &hints, &res);
         Py_END_ALLOW_THREADS
         /* We assume that those thread-unsafe getaddrinfo() versions
            *are* safe regarding their return value, ie. that a
            subsequent call to getaddrinfo() does not destroy the
            outcome of the first call. */
-        RELEASE_GETADDRINFO_LOCK
         if (error) {
             set_gaierror(error);
             return -1;
@@ -1194,7 +1155,6 @@
     memset(&hints, 0, sizeof(hints));
     hints.ai_family = af;
     Py_BEGIN_ALLOW_THREADS
-    ACQUIRE_GETADDRINFO_LOCK
     error = getaddrinfo(name, NULL, &hints, &res);
 #if defined(__digital__) && defined(__unix__)
     if (error == EAI_NONAME && af == AF_UNSPEC) {
@@ -1205,7 +1165,6 @@
     }
 #endif
     Py_END_ALLOW_THREADS
-    RELEASE_GETADDRINFO_LOCK  /* see comment in setipaddr() */
     if (error) {
         set_gaierror(error);
         return -1;
@@ -6563,10 +6522,8 @@
     hints.ai_protocol = protocol;
     hints.ai_flags = flags;
     Py_BEGIN_ALLOW_THREADS
-    ACQUIRE_GETADDRINFO_LOCK
     error = getaddrinfo(hptr, pptr, &hints, &res0);
     Py_END_ALLOW_THREADS
-    RELEASE_GETADDRINFO_LOCK  /* see comment in setipaddr() */
     if (error) {
         set_gaierror(error);
         goto err;
@@ -6659,10 +6616,8 @@
     hints.ai_socktype = SOCK_DGRAM;     /* make numeric port happy */
     hints.ai_flags = AI_NUMERICHOST;    /* don't do any name resolution */
     Py_BEGIN_ALLOW_THREADS
-    ACQUIRE_GETADDRINFO_LOCK
     error = getaddrinfo(hostp, pbuf, &hints, &res);
     Py_END_ALLOW_THREADS
-    RELEASE_GETADDRINFO_LOCK  /* see comment in setipaddr() */
     if (error) {
         set_gaierror(error);
         goto fail;
@@ -8422,7 +8377,7 @@
 #endif /* _MSTCPIP_ */
 
     /* Initialize gethostbyname lock */
-#if defined(USE_GETHOSTBYNAME_LOCK) || defined(USE_GETADDRINFO_LOCK)
+#if defined(USE_GETHOSTBYNAME_LOCK)
     netdb_lock = PyThread_allocate_lock();
 #endif