diff --git a/tests/unit/test_tmem_4warp_read.cu b/tests/unit/test_tmem_4warp_read.cu
index 3a3b8b97..c7ee6678 100644
--- a/tests/unit/test_tmem_4warp_read.cu
+++ b/tests/unit/test_tmem_4warp_read.cu
@@ -133,7 +133,7 @@ int main() {
     // SMEM: sbuf(8) + sRowMax(512) + align(128) + sQ0(4096) + sK0(4096) + slack(256) = 9000
     size_t smem_off = 8 + 128*4;
     smem_off = ((smem_off + 127) & ~(size_t)127);
-    smem_off += TILE_SZ * 2 + 256;
+    smem_off += TILE_SZ * 2 * 2 + 256;  // sQ0 + sK0 (each TILE_SZ BF16 = 4096 bytes) + slack
     int smem = (int)smem_off;
 
     test_mma_rows<<<1, 192, smem>>>(d_r);