diff --git a/InterfaceGenerator.Tests/SameName/SameNameClass.1.cs b/InterfaceGenerator.Tests/SameName/SameNameClass.1.cs
new file mode 100644
index 0000000..e3906f2
--- /dev/null
+++ b/InterfaceGenerator.Tests/SameName/SameNameClass.1.cs
@@ -0,0 +1,12 @@
+// ReSharper disable CheckNamespace
+namespace InterfaceGenerator.Tests.SameName_1;
+
+/// <summary>
+/// A class with the same name as <see cref="SameName_2.SameNameClass"/>. It exists to test if the generated source units have fully
+/// qualified names.
+/// </summary>
+[GenerateAutoInterface]
+internal class SameNameClass : ISameNameClass
+{
+    
+}
\ No newline at end of file
diff --git a/InterfaceGenerator.Tests/SameName/SameNameClass.2.cs b/InterfaceGenerator.Tests/SameName/SameNameClass.2.cs
new file mode 100644
index 0000000..9147b4f
--- /dev/null
+++ b/InterfaceGenerator.Tests/SameName/SameNameClass.2.cs
@@ -0,0 +1,8 @@
+// ReSharper disable CheckNamespace
+namespace InterfaceGenerator.Tests.SameName_2;
+
+[GenerateAutoInterface]
+internal class SameNameClass : ISameNameClass
+{
+    
+}
\ No newline at end of file
diff --git a/InterfaceGenerator/AutoInterfaceGenerator.cs b/InterfaceGenerator/AutoInterfaceGenerator.cs
index 026ed36..c7b2852 100644
--- a/InterfaceGenerator/AutoInterfaceGenerator.cs
+++ b/InterfaceGenerator/AutoInterfaceGenerator.cs
@@ -1,6 +1,7 @@
 using System;
 using System.CodeDom.Compiler;
 using System.Collections.Generic;
+using System.Diagnostics;
 using System.Globalization;
 using System.IO;
 using System.Linq;
@@ -21,6 +22,14 @@ namespace InterfaceGenerator
         public void Initialize(GeneratorInitializationContext context)
         {
             context.RegisterForSyntaxNotifications(() => new SyntaxReceiver());
+
+            #if DEBUG
+            if (!Debugger.IsAttached)
+            {
+                // sadly this is Windows only so as of now :(
+                Debugger.Launch();
+            }
+            #endif
         }
 
         public void Execute(GeneratorExecutionContext context)
@@ -83,6 +92,8 @@ namespace InterfaceGenerator
 
             var classSymbols = GetImplTypeSymbols(compilation, receiver);
 
+            List<string> classSymbolNames = new List<string>();
+
             foreach (var implTypeSymbol in classSymbols)
             {
                 if (!implTypeSymbol.TryGetAttribute(_generateAutoInterfaceAttribute, out var attributes))
@@ -90,9 +101,17 @@ namespace InterfaceGenerator
                     continue;
                 }
 
+                if(classSymbolNames.Contains(implTypeSymbol.GetFullMetadataName(useNameWhenNotFound: true)))
+                {
+                    continue; // partial class, already added
+                }
+
+                classSymbolNames.Add(implTypeSymbol.GetFullMetadataName(useNameWhenNotFound: true));
+
                 var attribute = attributes.Single(); 
                 var source = SourceText.From(GenerateInterfaceCode(implTypeSymbol, attribute), Encoding.UTF8);
-                context.AddSource($"{implTypeSymbol.Name}_AutoInterface.cs", source);
+
+                context.AddSource($"{implTypeSymbol.GetFullMetadataName(useNameWhenNotFound: true)}_AutoInterface.cs", source);
             }
         }
 
diff --git a/InterfaceGenerator/SymbolExtensions.cs b/InterfaceGenerator/SymbolExtensions.cs
index bb1fbce..5f309ae 100644
--- a/InterfaceGenerator/SymbolExtensions.cs
+++ b/InterfaceGenerator/SymbolExtensions.cs
@@ -1,5 +1,6 @@
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
 using Microsoft.CodeAnalysis;
 
 namespace InterfaceGenerator
@@ -21,5 +22,47 @@ namespace InterfaceGenerator
             return symbol.GetAttributes()
                          .Any(a => SymbolEqualityComparer.Default.Equals(a.AttributeClass, attributeType));
         }
+
+        //Ref: https://stackoverflow.com/questions/27105909/get-fully-qualified-metadata-name-in-roslyn
+        public static string GetFullMetadataName(this ISymbol symbol, bool useNameWhenNotFound = false)
+        {
+            if (IsRootNamespace(symbol))
+            {
+                return useNameWhenNotFound ? symbol.Name : string.Empty;
+            }
+
+            var stringBuilder = new StringBuilder(symbol.MetadataName);
+            var last = symbol;
+
+            symbol = symbol.ContainingSymbol;
+
+            while (!IsRootNamespace(symbol))
+            {
+                if (symbol is ITypeSymbol && last is ITypeSymbol)
+                {
+                    stringBuilder.Insert(0, '+');
+                }
+                else
+                {
+                    stringBuilder.Insert(0, '.');
+                }
+
+                stringBuilder.Insert(0, symbol.OriginalDefinition.ToDisplayString(SymbolDisplayFormat.MinimallyQualifiedFormat));
+                symbol = symbol.ContainingSymbol;
+            }
+
+            var retVal = stringBuilder.ToString();
+            if (string.IsNullOrWhiteSpace(retVal) && useNameWhenNotFound)
+            {
+                return symbol.Name;
+            }
+
+            return retVal;
+        }
+
+        private static bool IsRootNamespace(ISymbol symbol)
+        {
+            return symbol is INamespaceSymbol { IsGlobalNamespace: true };
+        }
     }
 }
\ No newline at end of file