1 files changed, 2 insertions, 0 deletions
diff --git a/src/Module.zig b/src/Module.zig
index bf278fb9b5..9d5f4a69d2 100644
--- a/src/Module.zig
+++ b/src/Module.zig
@@ -2637,6 +2637,8 @@ comptime {
 }
 
 pub fn astGenFile(mod: *Module, file: *File) !void {
+    assert(!file.mod.isBuiltin());
+
     const tracy = trace(@src());
     defer tracy.end();