diff --git a/scripts/update_api.py b/scripts/update_api.py
index b8978ff21..031b39c75 100755
--- a/scripts/update_api.py
+++ b/scripts/update_api.py
@@ -365,7 +365,7 @@ def mk_dotnet(dotnet):
     dotnet.write('        public delegate void Z3_error_handler(Z3_context c, Z3_error_code e);\n\n')
     dotnet.write('        public class LIB\n')
     dotnet.write('        {\n')
-    dotnet.write('            const string Z3_DLL_NAME = \"libz3.dll\";\n'
+    dotnet.write('            const string Z3_DLL_NAME = \"libz3\";\n'
                  '            \n')
     dotnet.write('            [DllImport(Z3_DLL_NAME, CallingConvention = CallingConvention.Cdecl, CharSet = CharSet.Ansi)]\n')
     dotnet.write('            public extern static void Z3_set_error_handler(Z3_context a0, Z3_error_handler a1);\n\n')
diff --git a/src/api/dotnet/core/DummyContracts.cs b/src/api/dotnet/core/DummyContracts.cs
index e0002e5be..49b498b1a 100644
--- a/src/api/dotnet/core/DummyContracts.cs
+++ b/src/api/dotnet/core/DummyContracts.cs
@@ -44,15 +44,21 @@ namespace System.Diagnostics.Contracts
 
     public static class Contract
     {
+        [Conditional("false")]
         public static void Ensures(bool b) { }
+        [Conditional("false")]
         public static void Requires(bool b) { }
+        [Conditional("false")]
         public static void Assume(bool b, string msg) { }
+        [Conditional("false")]
         public static void Assert(bool b) { }
         public static bool ForAll(bool b) { return true; }
         public static bool ForAll(Object c, Func<Object, bool> p) { return true; }
         public static bool ForAll(int from, int to, Predicate<int> p) { return true; }
+        [Conditional("false")]
         public static void Invariant(bool b) { }
         public static T[] Result<T>() { return new T[1]; }
+        [Conditional("false")]
         public static void EndContractBlock() { }
         public static T ValueAtReturn<T>(out T v) { T[] t = new T[1]; v = t[0]; return v; }
     }