diff --git a/build/Helpers.lua b/build/Helpers.lua
index e2409ae2..d852c78b 100644
--- a/build/Helpers.lua
+++ b/build/Helpers.lua
@@ -19,6 +19,10 @@ gcc_buildflags = { "-std=gnu++11" }
 
 msvc_cpp_defines = { }
 
+function SafePath(path)
+  return "\"" .. path .. "\""
+end
+
 function SetupNativeProject()
   location (path.join(builddir, "projects"))
 
diff --git a/build/Tests.lua b/build/Tests.lua
index c4d6d7e0..c1260f26 100644
--- a/build/Tests.lua
+++ b/build/Tests.lua
@@ -55,6 +55,11 @@ function LinkNUnit()
   }
 end
 
+function SetupTestGen(name)
+  local exePath = SafePath("$(TargetDir)" .. name .. ".Gen.exe")
+  prebuildcommands { exePath }
+end
+
 function SetupTestProjects(name, file, lib)
   project(name .. ".CSharp")
 
@@ -64,6 +69,7 @@ function SetupTestProjects(name, file, lib)
     flags { "Unsafe" }
     
     dependson { name .. ".Gen" }
+    SetupTestGen(name)
 
     files
     {
@@ -77,6 +83,7 @@ function SetupTestProjects(name, file, lib)
     flags { "Managed" }
 
     dependson { name .. ".Gen" }
+    SetupTestGen(name)
 
     files
     {