diff --git a/src/BuiltinFn.zig b/src/BuiltinFn.zig
index aa0ba0515df7c3972b707f428033f01cc339d81e..a3af727426546d578c24ce5b7b19f127bea4afbd 100644
--- a/src/BuiltinFn.zig
+++ b/src/BuiltinFn.zig
@@ -153,7 +153,7 @@ pub const list = list: {
             "@asyncCall",
             .{
                 .tag = .async_call,
-                .param_count = null,
+                .param_count = 4,
             },
         },
         .{