diff --git a/ggml/src/ggml-cuda/fattn.cu b/ggml/src/ggml-cuda/fattn.cu
index ae5a3507..b2c744ac 100644
--- a/ggml/src/ggml-cuda/fattn.cu
+++ b/ggml/src/ggml-cuda/fattn.cu
@@ -13,6 +13,7 @@
 #include "fattn-mma-f16-interface.cuh"
 #include "fattn-new-mma.cuh"
 #include "fattn.cuh"
+#include "convert.cuh"
 
 #include <cstdint>
 
@@ -106,6 +107,51 @@ void ggml_cuda_flash_attn_ext(ggml_backend_cuda_context & ctx, ggml_tensor * dst
     // Hence, we use it only for DeepSeek with MLA enabled, where head sizes are 576, 512,
     // so no other implementation works.
     //
+    if (new_mma_available(cc) && K->ne[0] == 576 && V->ne[0] == 512 && Q->ne[1] == 1 &&
+            Q->ne[2]/K->ne[2] == 20 && K->ne[1] > 8192) {
+        // GLM-4.7-Flash TG hack: split 20 heads into 16+4 heads
+        auto local_Q   = *Q;
+        auto local_dst = *dst;
+
+        ggml_tensor local_K, local_V;
+        ggml_cuda_pool_alloc<half> K_f16(ctx.pool());
+        if (ggml_is_quantized(K->type)) {
+            // We need to dequantize here, else we will dequantize the same cache twice
+            K_f16.alloc(ggml_nelements(K));
+            to_fp16_cuda_t to_fp16 = ggml_get_to_fp16_cuda(K->type);
+            to_fp16(K->data, K_f16.ptr, 1, ggml_nelements(K), ctx.stream());
+
+            auto bs = ggml_blck_size(K->type);
+            auto ts = ggml_type_size(K->type);
+
+            local_K = *K;
+            local_K.data = K_f16.get();
+            local_K.type  = GGML_TYPE_F16;
+            local_K.nb[0] = sizeof(half);
+            local_K.nb[1] = local_K.nb[1]*bs*sizeof(half)/ts;
+            local_K.nb[2] = local_K.nb[2]*bs*sizeof(half)/ts;
+            local_K.nb[3] = local_K.nb[3]*bs*sizeof(half)/ts;
+            local_dst.src[1] = &local_K;
+
+            local_V = local_K;
+            local_V.ne[0] = V->ne[0];
+            local_dst.src[2] = &local_V;
+        }
+
+        local_Q.ne[2]  = 16;
+        local_dst.ne[1] = 16;
+        local_dst.src[0] = &local_Q;
+        ggml_cuda_flash_attn_ext_mma_new(ctx, &local_dst);
+
+        local_Q.ne[2] = 4;
+        local_Q.data = (char *)local_Q.data + local_Q.nb[2]*16;
+        local_dst.ne[1] = 4;
+        local_dst.data = (char *)local_dst.data + local_dst.nb[1]*16;
+        ggml_cuda_flash_attn_ext_mma_new(ctx, &local_dst);
+
+        return;
+    }
+
     if (new_mma_available(cc) && ((K->ne[0] == 576 && V->ne[0] == 512) || (K->ne[0] == 192 && V->ne[0] == 128 && mma_better_than_turing(cc)))) {
         //printf("Using ggml_cuda_flash_attn_ext_mma_new\n");
         ggml_cuda_flash_attn_ext_mma_new(ctx, dst);