diff --git a/NEWS b/NEWS
index 798897da5d7..8aeb463c9fb 100644
--- a/NEWS
+++ b/NEWS
@@ -5,6 +5,9 @@ PHP                                                                        NEWS
 
 10 Nov 2016, PHP 7.1.0RC6
 
+- Calendar:
+  . Fix integer overflows (Joshua Rogers)
+
 - Core:
   . Fixded bug #72736 (Slow performance when fetching large dataset with mysqli
     / PDO). (Dmitry)
diff --git a/ext/calendar/calendar.c b/ext/calendar/calendar.c
index 76248a6554c..b5d21a4dcde 100644
--- a/ext/calendar/calendar.c
+++ b/ext/calendar/calendar.c
@@ -12,7 +12,7 @@
    | obtain it through the world-wide-web, please send a note to          |
    | license@php.net so we can mail you a copy immediately.               |
    +----------------------------------------------------------------------+
-   | Authors: Shane Caraveo             <shane@caraveo.com>               | 
+   | Authors: Shane Caraveo             <shane@caraveo.com>               |
    |          Colin Viebrock            <colin@easydns.com>               |
    |          Hartmut Holzgraefe        <hholzgra@php.net>                |
    |          Wez Furlong               <wez@thebrainroom.com>            |
diff --git a/ext/calendar/gregor.c b/ext/calendar/gregor.c
index 069fe6eb5ae..4c91fa8d540 100644
--- a/ext/calendar/gregor.c
+++ b/ext/calendar/gregor.c
@@ -195,7 +195,7 @@ zend_long GregorianToSdn(
 						   int inputMonth,
 						   int inputDay)
 {
-	int year;
+	zend_long year;
 	int month;
 
 	/* check for invalid dates */
diff --git a/ext/calendar/julian.c b/ext/calendar/julian.c
index 904727ff042..6ab0854c3be 100644
--- a/ext/calendar/julian.c
+++ b/ext/calendar/julian.c
@@ -217,7 +217,7 @@ zend_long JulianToSdn(
 						int inputMonth,
 						int inputDay)
 {
-	int year;
+	zend_long year;
 	int month;
 
 	/* check for invalid dates */
diff --git a/ext/calendar/tests/gregoriantojd_overflow.phpt b/ext/calendar/tests/gregoriantojd_overflow.phpt
new file mode 100644
index 00000000000..a189cc80c35
--- /dev/null
+++ b/ext/calendar/tests/gregoriantojd_overflow.phpt
@@ -0,0 +1,10 @@
+--TEST--
+gregoriantojd()
+--SKIPIF--
+<?php include 'skipif.inc'; ?>
+--FILE--
+<?php
+echo gregoriantojd(5, 5, 6000000) . "\n";
+?>
+--EXPECT--
+2193176185
diff --git a/ext/calendar/tests/juliantojd_overflow.phpt b/ext/calendar/tests/juliantojd_overflow.phpt
new file mode 100644
index 00000000000..f2f5aa182d0
--- /dev/null
+++ b/ext/calendar/tests/juliantojd_overflow.phpt
@@ -0,0 +1,10 @@
+--TEST--
+juliantojd()
+--SKIPIF--
+<?php include 'skipif.inc'; ?>
+--FILE--
+<?php
+echo juliantojd(5, 5, 6000000000) . "\n";
+?>
+--EXPECT--
+622764916319