diff --git a/vllm/attention/ops/triton_unified_attention.py b/vllm/attention/ops/triton_unified_attention.py
index 56ebed0f52448..250e9b3890444 100644
--- a/vllm/attention/ops/triton_unified_attention.py
+++ b/vllm/attention/ops/triton_unified_attention.py
@@ -674,7 +674,8 @@ def unified_attention(
     num_queries_per_kv = num_query_heads // num_kv_heads
     head_size = q.shape[2]
 
-    BLOCK_M = 16
+    BLOCK_M = 16 if num_queries_per_kv <= 16 else triton.next_power_of_2(
+        num_queries_per_kv)
     BLOCK_Q = BLOCK_M // num_queries_per_kv
 
     # Ideally we would launch with kernel with: