diff --git a/NEWS b/NEWS
index f9c9839d8f7..7245e6be83e 100644
--- a/NEWS
+++ b/NEWS
@@ -141,6 +141,7 @@ PHP                                                                        NEWS
 - Fixed bug #51445 (var_dump() invalid/slow *RECURSION* detection). (Felipe)
 - Fixed bug #51435 (Missing ifdefs / logic bug in crypt code cause compile
   errors). (Felipe)
+- Fixed bug #51424 (crypt() function hangs after 3rd call). (Pierre)
 - Fixed bug #51394 (Error line reported incorrectly if error handler throws an 
   exception). (Stas)
 - Fixed bug #51393 (DateTime::createFromFormat() fails if format string contains
diff --git a/ext/standard/php_crypt_r.c b/ext/standard/php_crypt_r.c
index d04d4dd78df..91063003e76 100644
--- a/ext/standard/php_crypt_r.c
+++ b/ext/standard/php_crypt_r.c
@@ -81,11 +81,13 @@ void _crypt_extended_init_r(void)
 	tsrm_mutex_lock(php_crypt_extended_init_lock);
 #endif
 
-	if (initialized) {
-		return;
-	} else {
+	if (!initialized) {
+#ifdef PHP_WIN32
+		InterlockedIncrement(initialized);
+#elif (defined(__GNUC__) && (__GNUC__ >= 4 && __GNUC_MINOR >= 2))
+		__sync_fetch_and_add(&initialized, 1);
+#endif
 		_crypt_extended_init();
-		initialized = 1;
 	}
 #ifdef ZTS
 	tsrm_mutex_unlock(php_crypt_extended_init_lock);