diff --git a/python/sglang/srt/managers/scheduler_metrics_mixin.py b/python/sglang/srt/managers/scheduler_metrics_mixin.py
index 53714c9ed..2dd6511ef 100644
--- a/python/sglang/srt/managers/scheduler_metrics_mixin.py
+++ b/python/sglang/srt/managers/scheduler_metrics_mixin.py
@@ -274,9 +274,12 @@ class SchedulerMetricsMixin:
                 self.spec_num_accepted_tokens / self.spec_num_forward_ct
             )
             # Calculate acceptance rate: accepted tokens / total draft tokens
-            total_draft_tokens = self.spec_num_forward_ct * (
-                (self.server_args.speculative_num_steps or 0) + 1
+            draft_tokens_fallback = (self.server_args.speculative_num_steps or 0) + 1
+            num_draft_tokens = (
+                self.server_args.speculative_num_draft_tokens or draft_tokens_fallback
             )
+            total_draft_tokens = self.spec_num_forward_ct * num_draft_tokens
+
             spec_accept_rate = (
                 self.spec_num_accepted_tokens / total_draft_tokens
                 if total_draft_tokens > 0