diff --git a/ggml/src/ggml-vulkan/ggml-vulkan.cpp b/ggml/src/ggml-vulkan/ggml-vulkan.cpp
index 6cf501e4e..87571cd57 100644
--- a/ggml/src/ggml-vulkan/ggml-vulkan.cpp
+++ b/ggml/src/ggml-vulkan/ggml-vulkan.cpp
@@ -9178,12 +9178,18 @@ static void ggml_vk_mul_mat_q_f16(ggml_backend_vk_context * ctx, vk_context& sub
 
     bool quantize_y = ctx->device->integer_dot_product && src1->type == GGML_TYPE_F32 && ggml_is_contiguous(src1) && !y_non_contig && (ne11 * ne10) % 4 == 0;
 
+    // DT3 weights (d1*t1 + d2*t2, two fp16-scaled ternary planes) already pay
+    // one fp16 rounding in the dequant fallback; fp16 accumulation on top of
+    // it costs measurable perplexity. Force fp32 accumulators, matching the
+    // numerics of the CUDA GEMM fallback (fp16 inputs, fp32 compute).
+    const ggml_prec mm_prec = src0->type == GGML_TYPE_DT3 ? GGML_PREC_F32 : (ggml_prec)dst->op_params[0];
+
     // Check for mmq first
-    vk_matmul_pipeline mmp = quantize_y ? ggml_vk_get_mul_mat_mat_pipeline(ctx, src0->type, GGML_TYPE_Q8_1, (ggml_prec)dst->op_params[0]) : nullptr;
+    vk_matmul_pipeline mmp = quantize_y ? ggml_vk_get_mul_mat_mat_pipeline(ctx, src0->type, GGML_TYPE_Q8_1, mm_prec) : nullptr;
 
     if (mmp == nullptr) {
         // Fall back to f16 dequant mul mat
-        mmp = ggml_vk_get_mul_mat_mat_pipeline(ctx, src0->type, y_non_contig ? f16_type : src1->type, (ggml_prec)dst->op_params[0]);
+        mmp = ggml_vk_get_mul_mat_mat_pipeline(ctx, src0->type, y_non_contig ? f16_type : src1->type, mm_prec);
         quantize_y = false;
     }
 
@@ -9192,7 +9198,7 @@ static void ggml_vk_mul_mat_q_f16(ggml_backend_vk_context * ctx, vk_context& sub
 
     if (qx_needs_dequant) {
         // Fall back to dequant + f16 mulmat
-        mmp = ggml_vk_get_mul_mat_mat_pipeline(ctx, f16_type, y_f32_kernel ? GGML_TYPE_F32 : f16_type, (ggml_prec)dst->op_params[0]);
+        mmp = ggml_vk_get_mul_mat_mat_pipeline(ctx, f16_type, y_f32_kernel ? GGML_TYPE_F32 : f16_type, mm_prec);
     }
 
     // Not implemented