diff --git a/hutool-core/src/main/java/cn/hutool/core/date/format/FastDatePrinter.java b/hutool-core/src/main/java/cn/hutool/core/date/format/FastDatePrinter.java
index 4d60f18f4..b69e32b86 100644
--- a/hutool-core/src/main/java/cn/hutool/core/date/format/FastDatePrinter.java
+++ b/hutool-core/src/main/java/cn/hutool/core/date/format/FastDatePrinter.java
@@ -299,7 +299,7 @@ public class FastDatePrinter extends AbstractDateBasic implements DatePrinter {
 		} else if (obj instanceof Calendar) {
 			return format((Calendar) obj);
 		} else if (obj instanceof Long) {
-			return format(((Long) obj));
+			return format(((Long) obj).longValue());
 		} else {
 			throw new IllegalArgumentException("Unknown class: " + (obj == null ? "<null>" : obj.getClass().getName()));
 		}