diff --git a/NewLife.Core/Caching/MemoryCache.cs b/NewLife.Core/Caching/MemoryCache.cs
index 5c47eb65b..c6fb228d3 100644
--- a/NewLife.Core/Caching/MemoryCache.cs
+++ b/NewLife.Core/Caching/MemoryCache.cs
@@ -511,7 +511,7 @@ public void Set<T>(T value, Int32 expire)
             if (expire <= 0)
                 ExpiredTime = Int64.MaxValue;
             else
-                ExpiredTime = now + expire * 1000;
+                ExpiredTime = now + expire * 1000L;
         }
 
         /// <summary>设置数值和过期时间</summary>
diff --git a/XUnitTest.Core/Caching/MemoryCacheTests.cs b/XUnitTest.Core/Caching/MemoryCacheTests.cs
index 59e29f289..f7216d4e9 100644
--- a/XUnitTest.Core/Caching/MemoryCacheTests.cs
+++ b/XUnitTest.Core/Caching/MemoryCacheTests.cs
@@ -350,4 +350,25 @@ public void GetQueue()
         var ex = Assert.Throws<InvalidCastException>(() => mc.GetQueue<String>("queue"));
         Assert.StartsWith("Unable to convert the value of [queue]", ex.Message);
     }
+
+    [Theory]
+    [InlineData(3)]
+    [InlineData(24)]
+    [InlineData(25)]
+    [InlineData(3650)]
+    public void LongExpireSet(Int32 days)
+    {
+        var mc = new MemoryCache();
+
+        mc.Set("name", "Stone", TimeSpan.FromDays(days));
+
+        var rs = mc.ContainsKey("name");
+        Assert.True(rs);
+
+        var val = mc.Get<String>("name");
+        Assert.Equal("Stone", val);
+
+        var exp = mc.GetExpire("name");
+        Assert.Equal(days, exp.Days);
+    }
 }
\ No newline at end of file