diff --git a/ext/posix/posix.c b/ext/posix/posix.c
index 049d0bfdf19c..104d8bd659dd 100644
--- a/ext/posix/posix.c
+++ b/ext/posix/posix.c
@@ -51,6 +51,10 @@
 #define POSIX_PID_MAX INT_MAX
 #endif
 
+/* RLIM_INFINITY does not fit into a 32-bit zend_long if rlim_t is 64-bit.
+ * posix_setrlimit() maps -1 to RLIM_INFINITY, so use that in this case. */
+#define PHP_POSIX_RLIM_INFINITY (RLIM_INFINITY > ZEND_LONG_MAX ? -1 : (zend_long) RLIM_INFINITY)
+
 #include "posix_arginfo.h"
 
 ZEND_DECLARE_MODULE_GLOBALS(posix)
diff --git a/ext/posix/posix.stub.php b/ext/posix/posix.stub.php
index 2ee9cdbc3147..94aeba3b6401 100644
--- a/ext/posix/posix.stub.php
+++ b/ext/posix/posix.stub.php
@@ -187,7 +187,7 @@
 #ifdef HAVE_SETRLIMIT
 /**
  * @var int
- * @cvalue RLIM_INFINITY
+ * @cvalue PHP_POSIX_RLIM_INFINITY
  */
 const POSIX_RLIMIT_INFINITY = UNKNOWN;
 #endif
diff --git a/ext/posix/posix_arginfo.h b/ext/posix/posix_arginfo.h
index 6172cdf3a1ce..35a051b2ae72 100644
--- a/ext/posix/posix_arginfo.h
+++ b/ext/posix/posix_arginfo.h
@@ -1,5 +1,5 @@
 /* This is a generated file, edit posix.stub.php instead.
- * Stub hash: 25e0aa769d72988ebca07fff96c8ed1fcb6b7d5e */
+ * Stub hash: 058523eee3f040ad14c41bceca4068d877054892 */
 
 #include "zend_constants.h"
 
@@ -413,7 +413,7 @@ static void register_posix_symbols(int module_number)
 	REGISTER_LONG_CONSTANT("POSIX_RLIMIT_NPTS", RLIMIT_NPTS, CONST_PERSISTENT);
 #endif
 #if defined(HAVE_SETRLIMIT)
-	REGISTER_LONG_CONSTANT("POSIX_RLIMIT_INFINITY", RLIM_INFINITY, CONST_PERSISTENT);
+	REGISTER_LONG_CONSTANT("POSIX_RLIMIT_INFINITY", PHP_POSIX_RLIM_INFINITY, CONST_PERSISTENT);
 #endif
 #if defined(_SC_ARG_MAX)
 	REGISTER_LONG_CONSTANT("POSIX_SC_ARG_MAX", _SC_ARG_MAX, CONST_PERSISTENT);
diff --git a/ext/posix/tests/posix_setrlimit_infinity.phpt b/ext/posix/tests/posix_setrlimit_infinity.phpt
new file mode 100644
index 000000000000..c04878cb5aec
--- /dev/null
+++ b/ext/posix/tests/posix_setrlimit_infinity.phpt
@@ -0,0 +1,34 @@
+--TEST--
+posix_setrlimit() with POSIX_RLIMIT_INFINITY
+--EXTENSIONS--
+posix
+--SKIPIF--
+<?php
+if (!function_exists('posix_setrlimit')) die('skip posix_setrlimit() not found');
+if (posix_getrlimit(POSIX_RLIMIT_CORE)[1] !== 'unlimited') die('skip hard limit of POSIX_RLIMIT_CORE is not unlimited');
+?>
+--FILE--
+<?php
+
+var_dump(posix_setrlimit(POSIX_RLIMIT_CORE, 1024, POSIX_RLIMIT_INFINITY));
+var_dump(posix_getrlimit(POSIX_RLIMIT_CORE));
+
+var_dump(posix_setrlimit(POSIX_RLIMIT_CORE, POSIX_RLIMIT_INFINITY, POSIX_RLIMIT_INFINITY));
+var_dump(posix_getrlimit(POSIX_RLIMIT_CORE));
+
+?>
+--EXPECT--
+bool(true)
+array(2) {
+  [0]=>
+  int(1024)
+  [1]=>
+  string(9) "unlimited"
+}
+bool(true)
+array(2) {
+  [0]=>
+  string(9) "unlimited"
+  [1]=>
+  string(9) "unlimited"
+}