diff --git a/build.bat b/build.bat
index 669a2a6..3df2335 100644
--- a/build.bat
+++ b/build.bat
@@ -3,8 +3,8 @@ call "..\misc\compile_setup.bat"
 
 bld --dont_compile_core
 cd build
-rem core_main.exe rtsgame/main.core
-core_main.exe examples/unions.core
+core_main.exe rtsgame/main.core
+rem core_main.exe examples/unions.core
 bld --dont_compile_core --link=vendor/raylib/windows/raylibdll.lib
 rem build\generated_main.exe
 cd ..
diff --git a/core_codegen_c_language.cpp b/core_codegen_c_language.cpp
index bfd2bdb..d9b6729 100644
--- a/core_codegen_c_language.cpp
+++ b/core_codegen_c_language.cpp
@@ -582,7 +582,7 @@ gen_ast(Ast *ast) {
 
         CASE(RETURN, Return) {
             gen("return ");
-            gen_expr(node->expr);
+            if (node->expr) gen_expr(node->expr);
             gen(";");
             BREAK();
         }