diff --git a/src/intel/compiler/brw_fs.h b/src/intel/compiler/brw_fs.h
index 3f9d09541f3..ab29e86dc1e 100644
--- a/src/intel/compiler/brw_fs.h
+++ b/src/intel/compiler/brw_fs.h
@@ -137,7 +137,7 @@ struct fs_thread_payload : public thread_payload {
    uint8_t dest_depth_reg[2];
    uint8_t sample_pos_reg[2];
    uint8_t sample_mask_in_reg[2];
-   uint8_t depth_w_coef_reg[2];
+   uint8_t depth_w_coef_reg;
    uint8_t barycentric_coord_reg[BRW_BARYCENTRIC_MODE_COUNT][2];
 };
 
diff --git a/src/intel/compiler/brw_fs_thread_payload.cpp b/src/intel/compiler/brw_fs_thread_payload.cpp
index 3e64c097d56..79e4eba53be 100644
--- a/src/intel/compiler/brw_fs_thread_payload.cpp
+++ b/src/intel/compiler/brw_fs_thread_payload.cpp
@@ -210,12 +210,13 @@ setup_fs_payload_gfx6(fs_thread_payload &payload,
          payload.sample_mask_in_reg[j] = payload.num_regs;
          payload.num_regs += payload_width / 8;
       }
+   }
 
-      /* R66: Source Depth and/or W Attribute Vertex Deltas */
-      if (prog_data->uses_depth_w_coefficients) {
-         payload.depth_w_coef_reg[j] = payload.num_regs;
-         payload.num_regs++;
-      }
+   /* R66: Source Depth and/or W Attribute Vertex Deltas */
+   if (prog_data->uses_depth_w_coefficients) {
+      assert(v.max_polygons == 1);
+      payload.depth_w_coef_reg = payload.num_regs;
+      payload.num_regs++;
    }
 
    if (v.nir->info.outputs_written & BITFIELD64_BIT(FRAG_RESULT_DEPTH)) {
diff --git a/src/intel/compiler/brw_fs_visitor.cpp b/src/intel/compiler/brw_fs_visitor.cpp
index 375afb8269c..644f8396a89 100644
--- a/src/intel/compiler/brw_fs_visitor.cpp
+++ b/src/intel/compiler/brw_fs_visitor.cpp
@@ -435,7 +435,7 @@ fs_visitor::emit_interpolation_setup_gfx6()
        * pixels locations, here we recompute the Z value with 2 coefficients
        * in X & Y axis.
        */
-      fs_reg coef_payload = fetch_payload_reg(abld, fs_payload().depth_w_coef_reg, BRW_REGISTER_TYPE_F);
+      fs_reg coef_payload = brw_vec8_grf(fs_payload().depth_w_coef_reg, 0);
       const fs_reg x_start = brw_vec1_grf(coef_payload.nr, 2);
       const fs_reg y_start = brw_vec1_grf(coef_payload.nr, 6);
       const fs_reg z_cx    = brw_vec1_grf(coef_payload.nr, 1);