diff --git a/src/Generator/Generators/CSharp/CSharpSources.cs b/src/Generator/Generators/CSharp/CSharpSources.cs
index 182cf11d..c4e3c73b 100644
--- a/src/Generator/Generators/CSharp/CSharpSources.cs
+++ b/src/Generator/Generators/CSharp/CSharpSources.cs
@@ -2945,7 +2945,7 @@ namespace CppSharp.Generators.CSharp
                 to = to.OriginalClass ?? to;
                 baseOffset = GetOffsetToBase(from, to);
             }
-            var isPrimaryBase = from.BaseClass == to;
+            var isPrimaryBase = (from.BaseClass?.OriginalClass ?? from.BaseClass) == to;
             if (isPrimaryBase)
             {
                 return string.Format("({0} + {1}{2})",
diff --git a/src/Generator/Passes/MultipleInheritancePass.cs b/src/Generator/Passes/MultipleInheritancePass.cs
index 6fdc4edb..975c73ad 100644
--- a/src/Generator/Passes/MultipleInheritancePass.cs
+++ b/src/Generator/Passes/MultipleInheritancePass.cs
@@ -15,6 +15,11 @@ namespace CppSharp.Passes
         /// </summary>
         private readonly HashSet<Class> interfaces = new HashSet<Class>();
 
+        /// <summary>
+        /// Change and implement secondaryy bases at the end to avoid processing implementations.
+        /// </summary>
+        private readonly HashSet<Class> classesWithSecondaryBases = new HashSet<Class>();
+
         public MultipleInheritancePass()
         {
             VisitOptions.VisitClassFields = false;
@@ -35,26 +40,40 @@ namespace CppSharp.Passes
                 int index = @interface.Namespace.Declarations.IndexOf(@interface.OriginalClass);
                 @interface.Namespace.Declarations.Insert(index, @interface);
             }
+
+            foreach (Class @class in classesWithSecondaryBases)
+            {
+                for (var i = 1; i < @class.Bases.Count; i++)
+                {
+                    var @base = @class.Bases[i];
+                    Class @interface = interfaces.FirstOrDefault(iface => iface.OriginalClass == @base.Class);
+                    if (@interface == null)
+                        continue;
+                    @class.Bases[i] = new BaseClassSpecifier(@base) { Type = new TagType(@interface) };
+                    ImplementInterfaceMethods(@class, @interface);
+                    ImplementInterfaceProperties(@class, @interface);
+                }
+            }
+
             interfaces.Clear();
+            classesWithSecondaryBases.Clear();
             return result;
         }
 
         public override bool VisitClassDecl(Class @class)
         {
-            if (!base.VisitClassDecl(@class) || !@class.IsGenerated)
+            if (!base.VisitClassDecl(@class) || !@class.IsGenerated || @class.Bases.Count == 1)
                 return false;
 
+            classesWithSecondaryBases.Add(@class);
+
             // skip the first base because we can inherit from one class
             for (var i = 1; i < @class.Bases.Count; i++)
             {
                 var @base = @class.Bases[i];
                 var baseClass = @base.Class;
                 if (baseClass == null || baseClass.IsInterface || !baseClass.IsGenerated) continue;
-
-                var @interface = GetInterface(baseClass);
-                @class.Bases[i] = new BaseClassSpecifier(@base) { Type = new TagType(@interface) };
-                ImplementInterfaceMethods(@class, @interface);
-                ImplementInterfaceProperties(@class, @interface);
+                GetInterface(baseClass);
             }
             return true;
         }
diff --git a/tests/CSharp/CSharp.Tests.cs b/tests/CSharp/CSharp.Tests.cs
index 42f13a7d..f06c4e1f 100644
--- a/tests/CSharp/CSharp.Tests.cs
+++ b/tests/CSharp/CSharp.Tests.cs
@@ -371,13 +371,20 @@ public unsafe class CSharpTests : GeneratorTestFixture
     [Test]
     public void TestPrimarySecondaryBase()
     {
-        var a = new MI_A0();
-        var resa = a.Get();
-        Assert.That(resa, Is.EqualTo(50));
+        using (var a = new MI_A0())
+        {
+            Assert.That(a.Get(), Is.EqualTo(50));
+        }
 
-        var c = new MI_C();
-        var res = c.Get();
-        Assert.That(res, Is.EqualTo(50));
+        using (var c = new MI_C())
+        {
+            Assert.That(c.Get(), Is.EqualTo(50));
+        }
+
+        using (var d = new MI_D())
+        {
+            Assert.That(d.Get(), Is.EqualTo(50));
+        }
     }
 
     [Test]
diff --git a/tests/CSharp/CSharp.h b/tests/CSharp/CSharp.h
index 8df775a5..5a344000 100644
--- a/tests/CSharp/CSharp.h
+++ b/tests/CSharp/CSharp.h
@@ -580,6 +580,20 @@ struct DLL_API MI_C : public MI_A0, public MI_B
 
 MI_C::MI_C() {}
 
+struct DLL_API MI_A1
+{
+    MI_A1();
+};
+
+MI_A1::MI_A1() {}
+
+struct DLL_API MI_D : public MI_A1, public MI_C
+{
+    MI_D();
+};
+
+MI_D::MI_D() {}
+
 class DLL_API StructWithPrivateFields
 {
 public: