diff --git a/include/flashinfer/trtllm/fmha/fmhaKernels.cuh b/include/flashinfer/trtllm/fmha/fmhaKernels.cuh
index ca71bb0b88..e08820a694 100644
--- a/include/flashinfer/trtllm/fmha/fmhaKernels.cuh
+++ b/include/flashinfer/trtllm/fmha/fmhaKernels.cuh
@@ -611,8 +611,9 @@ class TllmGenFmhaKernel {
     float globalModelingKernelTime = FLT_MAX;
     // Loop over each candidate tile size.
     for (int tileSizeQ : candidateTileSizesQ) {
-      // Only consider candidates <= default tileSizeQ.
-      if (tileSizeQ > defaultTileSizeQ) {
+      // Only consider candidates <= default tileSizeQ and ensure each CTA processes full
+      // numHeadsQPerKv.
+      if (tileSizeQ > defaultTileSizeQ || tileSizeQ < params.mNumHeadsQPerKv) {
         continue;
       }