diff --git a/Speckle.InterfaceGenerator/SymbolExtensions.cs b/Speckle.InterfaceGenerator/SymbolExtensions.cs
index 0f0167e..7e1fbba 100644
--- a/Speckle.InterfaceGenerator/SymbolExtensions.cs
+++ b/Speckle.InterfaceGenerator/SymbolExtensions.cs
@@ -15,7 +15,7 @@ internal static class SymbolExtensions
             return t.Name;
         }
 
-        if (typeSymbol.SpecialType == SpecialType.None)
+        if (typeSymbol.SpecialType != SpecialType.None)
         {
             return typeSymbol.ToString();
         }