diff --git a/ext/calendar/easter.c b/ext/calendar/easter.c
index c319abd17fef..2832d0bdefe0 100644
--- a/ext/calendar/easter.c
+++ b/ext/calendar/easter.c
@@ -28,6 +28,7 @@ static void _cal_easter(INTERNAL_FUNCTION_PARAMETERS, bool gm)
 	struct tm te;
 	zend_long year, golden, solar, lunar, pfm, dom, tmp, easter, result;
 	zend_long method = CAL_EASTER_DEFAULT;
+	const zend_long max_year = ZEND_LONG_MAX / 1.25;
 	bool year_is_null = 1;
 
 	if (zend_parse_parameters(ZEND_NUM_ARGS(),
@@ -48,6 +49,11 @@ static void _cal_easter(INTERNAL_FUNCTION_PARAMETERS, bool gm)
 		}
 	}
 
+	if (year <= 0 || year > max_year) {
+		zend_argument_value_error(1, "must be between 1 and " ZEND_LONG_FMT, max_year);
+		RETURN_THROWS();
+	}
+
 	if (gm && (year<1970 || year>2037)) {				/* out of range for timestamps */
 		zend_argument_value_error(1, "must be between 1970 and 2037 (inclusive)");
 		RETURN_THROWS();
diff --git a/ext/calendar/tests/gh16228.phpt b/ext/calendar/tests/gh16228.phpt
new file mode 100644
index 000000000000..9ce80688195b
--- /dev/null
+++ b/ext/calendar/tests/gh16228.phpt
@@ -0,0 +1,26 @@
+--TEST--
+GH-16228 (easter_days, Overflow on year argument)
+--EXTENSIONS--
+calendar
+--FILE--
+<?php
+try {
+	easter_days(PHP_INT_MAX, 0);
+} catch (\ValueError $e) {
+	echo $e->getMessage() . PHP_EOL;
+}
+try {
+	easter_days(-1, 0);
+} catch (\ValueError $e) {
+	echo $e->getMessage() . PHP_EOL;
+}
+try {
+	easter_date(PHP_INT_MAX, 0);
+} catch (\ValueError $e) {
+	echo $e->getMessage() . PHP_EOL;
+}
+?>
+--EXPECTF--
+easter_days(): Argument #1 ($year) must be between 1 and %d
+easter_days(): Argument #1 ($year) must be between 1 and %d
+easter_date(): Argument #1 ($year) must be between 1 and %d