diff --git a/src/NHibernate.Test/DynamicEntity/DataProxyHandler.cs b/src/NHibernate.Test/DynamicEntity/DataProxyHandler.cs
index bce91d9424b..69d306147cf 100644
--- a/src/NHibernate.Test/DynamicEntity/DataProxyHandler.cs
+++ b/src/NHibernate.Test/DynamicEntity/DataProxyHandler.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections;
+using System.Runtime.CompilerServices;
 using NHibernate.Proxy.DynamicProxy;
 
 namespace NHibernate.Test.DynamicEntity
@@ -53,6 +54,11 @@ public object Intercept(InvocationInfo info)
 			{
 				return GetHashCode();
 			}
+			else if ("Equals".Equals(methodName))
+			{
+				// Redo the base object Equals implementation.
+				return RuntimeHelpers.Equals(info.Target, info.Arguments[0]);
+			}
 			return null;
 		}
 
diff --git a/src/NHibernate.Test/NHSpecificTest/GH1881/TestFixture.cs b/src/NHibernate.Test/NHSpecificTest/GH1881/TestFixture.cs
new file mode 100644
index 00000000000..96c454cf201
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH1881/TestFixture.cs
@@ -0,0 +1,33 @@
+using System;
+using System.Linq;
+using System.Reflection;
+using NHibernate.Collection;
+using NHibernate.Collection.Generic;
+using NHibernate.Proxy.DynamicProxy;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH1881
+{
+	[TestFixture]
+	[Obsolete]
+	public class TestFixture
+	{
+		[Test]
+		public void InterfacesShouldBeImplementedExplicitlyOnProxies()
+		{
+			var proxy = new ProxyFactory().CreateProxy(typeof(PersistentGenericBag<object>), null, typeof(ILazyInitializedCollection));
+			Assert.That(proxy, Is.Not.Null);
+
+			foreach (var method in proxy.GetType().GetMethods().Where(m => m.DeclaringType == typeof(ILazyInitializedCollection)))
+			{
+				// These attributes are what .NET uses for explicitly implemented interface methods
+				Assert.That(method.Attributes, Is.EqualTo(MethodAttributes.Private |
+				                                          MethodAttributes.Final |
+				                                          MethodAttributes.Virtual |
+				                                          MethodAttributes.HideBySig |
+				                                          MethodAttributes.NewSlot |
+				                                          MethodAttributes.SpecialName));
+			}
+		}
+	}
+}
diff --git a/src/NHibernate/Proxy/DynamicProxy/ProxyFactory.cs b/src/NHibernate/Proxy/DynamicProxy/ProxyFactory.cs
index ad0a79a60c3..c57e4e28e7a 100644
--- a/src/NHibernate/Proxy/DynamicProxy/ProxyFactory.cs
+++ b/src/NHibernate/Proxy/DynamicProxy/ProxyFactory.cs
@@ -118,7 +118,7 @@ private TypeInfo CreateUncachedProxyType(System.Type baseType, IReadOnlyCollecti
 			
 			// Provide a custom implementation of ISerializable
 			// instead of redirecting it back to the interceptor
-			foreach (MethodInfo method in ProxyBuilderHelper.GetProxiableMethods(baseType, interfaces).Where(method => method.DeclaringType != typeof(ISerializable)))
+			foreach (MethodInfo method in ProxyBuilderHelper.GetProxiableMethods(parentType, interfaces).Where(method => method.DeclaringType != typeof(ISerializable)))
 			{
 				ProxyMethodBuilder.CreateProxiedMethod(interceptorField, method, typeBuilder);
 			}
diff --git a/src/NHibernate/Proxy/ProxyBuilderHelper.cs b/src/NHibernate/Proxy/ProxyBuilderHelper.cs
index 94af19db95d..df32f3d06b4 100644
--- a/src/NHibernate/Proxy/ProxyBuilderHelper.cs
+++ b/src/NHibernate/Proxy/ProxyBuilderHelper.cs
@@ -137,7 +137,24 @@ internal static MethodBuilder GetObjectDataMethodBuilder(TypeBuilder typeBuilder
 		internal static MethodBuilder GenerateMethodSignature(string name, MethodInfo method, TypeBuilder typeBuilder)
 		{
 			//TODO: Should we use attributes of base method?
-			var methodAttributes = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual;
+			MethodAttributes methodAttributes;
+			if (method.DeclaringType.IsInterface)
+			{
+				// These are the attributes used for an explicit interface method implementation in .NET.
+				methodAttributes =
+					MethodAttributes.Private |
+					MethodAttributes.Final |
+					MethodAttributes.Virtual |
+					MethodAttributes.HideBySig |
+					MethodAttributes.NewSlot |
+					MethodAttributes.SpecialName;
+				// .NET uses an expanded name for explicit interface implementation methods.
+				name = typeBuilder.FullName + "." + method.DeclaringType.FullName + "." + name;
+			}
+			else
+			{
+				methodAttributes = MethodAttributes.Public | MethodAttributes.HideBySig | MethodAttributes.Virtual;
+			}
 
 			if (method.IsSpecialName)
 				methodAttributes |= MethodAttributes.SpecialName;