diff --git a/ClosedXML/Excel/CalcEngine/Functions/Lookup.cs b/ClosedXML/Excel/CalcEngine/Functions/Lookup.cs
index 801a195..dfd6c1b 100644
--- a/ClosedXML/Excel/CalcEngine/Functions/Lookup.cs
+++ b/ClosedXML/Excel/CalcEngine/Functions/Lookup.cs
@@ -17,7 +17,7 @@
             //ce.RegisterFunction("FORMULATEXT", , Formulatext); // Returns the formula at the given reference as text
             //ce.RegisterFunction("GETPIVOTDATA", , Getpivotdata); // Returns data stored in a PivotTable report
             ce.RegisterFunction("HLOOKUP", 3, 4, Hlookup); // Looks in the top row of an array and returns the value of the indicated cell
-            //ce.RegisterFunction("HYPERLINK", , Hyperlink); // Creates a shortcut or jump that opens a document stored on a network server, an intranet, or the Internet
+            ce.RegisterFunction("HYPERLINK", 1, 2, Hyperlink); // Creates a shortcut or jump that opens a document stored on a network server, an intranet, or the Internet
             //ce.RegisterFunction("INDEX", , Index); // Uses an index to choose a value from a reference or array
             //ce.RegisterFunction("INDIRECT", , Indirect); // Returns a reference indicated by a text value
             //ce.RegisterFunction("LOOKUP", , Lookup); // Looks up values in a vector or array
@@ -80,6 +80,13 @@
                 .Value;
         }
 
+        private static object Hyperlink(List<Expression> p)
+        {
+            String address = p[0];
+            String toolTip = p.Count == 2 ? p[1] : String.Empty;
+            return new XLHyperlink(address, toolTip);
+        }
+
         private static object Vlookup(List<Expression> p)
         {
             var lookup_value = p[0];
diff --git a/ClosedXML/Excel/CalcEngine/Functions/Text.cs b/ClosedXML/Excel/CalcEngine/Functions/Text.cs
index 8ff1da3..bbf58ca 100644
--- a/ClosedXML/Excel/CalcEngine/Functions/Text.cs
+++ b/ClosedXML/Excel/CalcEngine/Functions/Text.cs
@@ -39,7 +39,6 @@
             ce.RegisterFunction("TRIM", 1, Trim); // Removes spaces from text
             ce.RegisterFunction("UPPER", 1, Upper); // Converts text to uppercase
             ce.RegisterFunction("VALUE", 1, Value); // Converts a text argument to a number
-            ce.RegisterFunction("HYPERLINK", 2, Hyperlink);
         }
 
         private static object _Char(List<Expression> p)
@@ -300,13 +299,6 @@
             return (string)p[0];
         }
 
-        private static object Hyperlink(List<Expression> p)
-        {
-            String address = p[0];
-            String toolTip = p.Count == 2 ? p[1] : String.Empty;
-            return new XLHyperlink(address, toolTip);
-        }
-
         private static object Clean(List<Expression> p)
         {
             var s = (string)p[0];
diff --git a/ClosedXML_Tests/Excel/CalcEngine/LookupTests.cs b/ClosedXML_Tests/Excel/CalcEngine/LookupTests.cs
index a18e509..b7b7151 100644
--- a/ClosedXML_Tests/Excel/CalcEngine/LookupTests.cs
+++ b/ClosedXML_Tests/Excel/CalcEngine/LookupTests.cs
@@ -129,5 +129,20 @@
 
             Assert.Throws<CellReferenceException>(() => workbook.Evaluate(@"=VLOOKUP(20,Data!$B$2:$I$71,9,FALSE)"));
         }
+
+        [Test]
+        public void Hyperlink()
+        {
+            XLHyperlink hl;
+            hl = XLWorkbook.EvaluateExpr("HYPERLINK(\"http://github.com/ClosedXML/ClosedXML\")") as XLHyperlink;
+            Assert.IsNotNull(hl);
+            Assert.AreEqual("http://github.com/ClosedXML/ClosedXML", hl.ExternalAddress.ToString());
+            Assert.AreEqual(string.Empty, hl.Tooltip);
+
+            hl = XLWorkbook.EvaluateExpr("HYPERLINK(\"mailto:jsmith@github.com\", \"jsmith@github.com\")") as XLHyperlink;
+            Assert.IsNotNull(hl);
+            Assert.AreEqual("mailto:jsmith@github.com", hl.ExternalAddress.ToString());
+            Assert.AreEqual("jsmith@github.com", hl.Tooltip);
+        }
     }
 }