diff --git a/.github/workflows/slow.yml b/.github/workflows/slow.yml
index 68755972..9d5bc126 100644
--- a/.github/workflows/slow.yml
+++ b/.github/workflows/slow.yml
@@ -15,7 +15,7 @@ concurrency:
   cancel-in-progress: true
 
 env:
-  B2_OPTS: -q -j2 warnings-as-errors=on
+  B2_OPTS: -d+2 -q -j2 warnings-as-errors=on
   UBSAN_OPTIONS: print_stacktrace=1
   LSAN_OPTIONS: verbosity=1:log_threads=1
   ASAN_OPTIONS: detect_leaks=1:detect_stack_use_after_return=1