diff --git a/python/sglang/srt/server_args.py b/python/sglang/srt/server_args.py
index 9dd74c114..e5fbcaa83 100644
--- a/python/sglang/srt/server_args.py
+++ b/python/sglang/srt/server_args.py
@@ -5548,8 +5548,16 @@ class ServerArgs:
             # Skip validation if disaggregation mode is decode.
             if self.chunked_prefill_size > 0 and self.disaggregation_mode != "decode":
                 assert (
-                    self.chunked_prefill_size
-                ) <= envs.SGLANG_MORI_NUM_MAX_DISPATCH_TOKENS_PER_RANK.get(), "SGLANG_MORI_NUM_MAX_DISPATCH_TOKENS_PER_RANK (default 4096) must be larger or equal to chunked_prefill_size"
+                    self._required_mori_dispatch_tokens_per_rank()
+                ) <= envs.SGLANG_MORI_NUM_MAX_DISPATCH_TOKENS_PER_RANK.get(), (
+                    "SGLANG_MORI_NUM_MAX_DISPATCH_TOKENS_PER_RANK (default 4096) "
+                    "must be >= the per-rank MoRI dispatch tokens "
+                    "(chunked_prefill_size by default)"
+                )
+
+    def _required_mori_dispatch_tokens_per_rank(self) -> int:
+        """Max tokens a single rank dispatches through MoRI in one forward."""
+        return self.chunked_prefill_size
 
     def _handle_eplb_and_dispatch(self):
         if self.enable_eplb and (self.expert_distribution_recorder_mode is None):