diff --git a/lib/compiler/test_runner.zig b/lib/compiler/test_runner.zig
index 4f3b40656c..15ae84510a 100644
--- a/lib/compiler/test_runner.zig
+++ b/lib/compiler/test_runner.zig
@@ -136,7 +136,7 @@ fn mainServer() !void {
                         .leak = leak,
                         .fuzz = is_fuzz_test,
                         .log_err_count = std.math.lossyCast(
-                            @TypeOf(@as(std.zig.Server.Message.TestResults.Flags, undefined).log_err_count),
+                            @FieldType(std.zig.Server.Message.TestResults.Flags, "log_err_count"),
                             log_err_count,
                         ),
                     },