diff --git a/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Fixture.cs b/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Fixture.cs
new file mode 100644
index 00000000000..0ec20886442
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Fixture.cs
@@ -0,0 +1,20 @@
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH2621Enum
+{
+	public class Fixture : BugTestCase
+	{
+		[Test]
+		public void TestOk()
+		{
+			using (var s = OpenSession())
+			using (s.BeginTransaction())
+			{
+				var query = s.CreateQuery(
+					@"SELECT Name FROM NHibernate.Test.NHSpecificTest.GH2621Enum.ClassWithString ROOT WHERE ROOT.Kind = :kind");
+				query.SetParameter("kind", Kind.SomeKind);
+				Assert.DoesNotThrow(() => query.List());
+			}
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Mappings.hbm.xml b/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Mappings.hbm.xml
new file mode 100644
index 00000000000..0da735748dc
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Mappings.hbm.xml
@@ -0,0 +1,14 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2"
+           namespace="NHibernate.Test.NHSpecificTest.GH2621Enum"
+           assembly="NHibernate.Test"
+>
+  <class name="ClassWithString" >
+    <id name="Id">
+      <generator class="increment"/>
+    </id>
+    <property name="Name"/>
+    <property name="Kind"/>
+  </class>
+
+</hibernate-mapping>
diff --git a/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Model.cs b/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Model.cs
new file mode 100644
index 00000000000..1a7cd35b5ff
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH2621Enum/Model.cs
@@ -0,0 +1,15 @@
+namespace NHibernate.Test.NHSpecificTest.GH2621Enum
+{
+	public abstract class ClassWithString
+	{
+		public virtual int Id { get; set; }
+		public virtual string Name { get; set; }
+		public virtual string Kind { get; set; }
+	}
+
+	public enum Kind 
+	{
+		SomeKind,
+		SomeOtherKind
+	}
+}
diff --git a/src/NHibernate/Type/AbstractStringType.cs b/src/NHibernate/Type/AbstractStringType.cs
index 267ccec6da5..9d47aaf07ff 100644
--- a/src/NHibernate/Type/AbstractStringType.cs
+++ b/src/NHibernate/Type/AbstractStringType.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Data.Common;
 using System.Globalization;
@@ -58,6 +58,9 @@ public override void Set(DbCommand cmd, object value, int index, ISessionImpleme
 		{
 			var parameter = cmd.Parameters[index];
 
+			if (value is Enum)
+				value = value.ToString();
+
 			//Allow the driver to adjust the parameter for the value
 			session.Factory.ConnectionProvider.Driver.AdjustParameterForValue(parameter, SqlType, value);