diff --git a/ClosedXML/Excel/CalcEngine/Functions/MathTrig.cs b/ClosedXML/Excel/CalcEngine/Functions/MathTrig.cs
index b042a5e..d4fc266 100644
--- a/ClosedXML/Excel/CalcEngine/Functions/MathTrig.cs
+++ b/ClosedXML/Excel/CalcEngine/Functions/MathTrig.cs
@@ -215,7 +215,7 @@
 
         private static object Int(List<Expression> p)
         {
-            return (int)((double)p[0]);
+            return Math.Floor(p[0]);
         }
 
         private static object Ln(List<Expression> p)
diff --git a/ClosedXML_Tests/Excel/CalcEngine/MathTrigTests.cs b/ClosedXML_Tests/Excel/CalcEngine/MathTrigTests.cs
index be8bb17..dd2eeef 100644
--- a/ClosedXML_Tests/Excel/CalcEngine/MathTrigTests.cs
+++ b/ClosedXML_Tests/Excel/CalcEngine/MathTrigTests.cs
@@ -1,5 +1,4 @@
 using ClosedXML.Excel;
-using ClosedXML.Excel.CalcEngine;
 using ClosedXML.Excel.CalcEngine.Exceptions;
 using NUnit.Framework;
 using System;
@@ -12,7 +11,7 @@
     public class MathTrigTests
     {
         private readonly double tolerance = 1e-10;
-        
+
         [TestCase(1, 0.642092616)]
         [TestCase(2, -0.457657554)]
         [TestCase(3, -7.015252551)]
@@ -24,7 +23,7 @@
         [TestCase(9, -2.210845411)]
         [TestCase(10, 1.542351045)]
         [TestCase(11, -0.004425741)]
-        [TestCase(Math.PI*0.5, 0)]
+        [TestCase(Math.PI * 0.5, 0)]
         [TestCase(45, 0.617369624)]
         [TestCase(-2, 0.457657554)]
         [TestCase(-3, 7.015252551)]
@@ -217,5 +216,14 @@
         {
             Assert.Throws<DivisionByZeroException>(() => XLWorkbook.EvaluateExpr("CSCH(0)"));
         }
+
+        [TestCase(8.9, 8)]
+        [TestCase(-8.9, -9)]
+        public void Int(double input, double expected)
+        {
+            var actual = XLWorkbook.EvaluateExpr(string.Format(@"INT({0})", input.ToString(CultureInfo.InvariantCulture)));
+            Assert.AreEqual(expected, actual);
+
+        }
     }
 }