diff --git a/src/codegen.cpp b/src/codegen.cpp
index 3d4d2a8c317e0f360c8bce83f2d8e800995e6aee..89edfc641223ce3eb5c96a59ef461f83430bd7f0 100644
--- a/src/codegen.cpp
+++ b/src/codegen.cpp
@@ -9787,6 +9787,7 @@ static void prepend_c_type_to_decl_list(CodeGen *g, GenH *gen_h, ZigType *type_e
             zig_unreachable();
         case ZigTypeIdVoid:
         case ZigTypeIdUnreachable:
+            return;
         case ZigTypeIdBool:
             g->c_want_stdbool = true;
             return;