diff --git a/cpp/include/raft/distance/detail/pairwise_distance_gemm.h b/cpp/include/raft/distance/detail/pairwise_distance_gemm.h
index ea9ed77fb5..8dcccfc14f 100644
--- a/cpp/include/raft/distance/detail/pairwise_distance_gemm.h
+++ b/cpp/include/raft/distance/detail/pairwise_distance_gemm.h
@@ -66,7 +66,7 @@ struct PairwiseDistanceGemm {
   /// Warp-level tile size (concept: GemmShape)
   // This code section describes the size of MMA op
   using InstructionShape =
-    cutlass::gemm::GemmShape<16, 8, 8>;  // <- MMA Op tile M = 16, N = 8, K = 8
+    cutlass::gemm::GemmShape<16, 8, 4>;  // <- MMA Op tile M = 16, N = 8, K = 4
 
   /// Operation performed by GEMM
   using Operator = cutlass::arch::OpMultiplyAddFastF32;