diff --git a/src/amd/compiler/aco_instruction_selection.cpp b/src/amd/compiler/aco_instruction_selection.cpp
index 973ea15f56a..4785419d469 100644
--- a/src/amd/compiler/aco_instruction_selection.cpp
+++ b/src/amd/compiler/aco_instruction_selection.cpp
@@ -13183,8 +13183,11 @@ select_ps_epilog(Program* program, void* pinfo, ac_shader_config* config,
    struct aco_export_mrt mrts[MAX_DRAW_BUFFERS];
    unsigned mrt_num = 0;
 
-   if (einfo->broadcast_last_cbuf) {
-      for (unsigned i = 0; i <= einfo->broadcast_last_cbuf; i++) {
+   if (einfo->writes_all_cbufs) {
+      /* This will do nothing for color buffers with SPI_SHADER_COL_FORMAT=ZERO, so always
+       * iterate over all 8.
+       */
+      for (unsigned i = 0; i < 8; i++) {
          struct aco_export_mrt* mrt = &mrts[mrt_num];
          if (export_fs_mrt_color(&ctx, einfo, colors[0], i, mrt))
             mrt->target += mrt_num++;
diff --git a/src/amd/compiler/aco_shader_info.h b/src/amd/compiler/aco_shader_info.h
index 49f172f0bd5..5837f51cd5f 100644
--- a/src/amd/compiler/aco_shader_info.h
+++ b/src/amd/compiler/aco_shader_info.h
@@ -65,7 +65,7 @@ struct aco_ps_epilog_info {
    uint16_t color_types;
    bool clamp_color;
    bool skip_null_export;
-   unsigned broadcast_last_cbuf;
+   bool writes_all_cbufs;
    enum compare_func alpha_func;
    /* Depth/stencil/samplemask are always passed via VGPRs, and the epilog key can choose
     * not to export them using these flags, which can be dynamic states.
diff --git a/src/gallium/drivers/radeonsi/si_shader_aco.c b/src/gallium/drivers/radeonsi/si_shader_aco.c
index c89926580a6..edb0e3015ca 100644
--- a/src/gallium/drivers/radeonsi/si_shader_aco.c
+++ b/src/gallium/drivers/radeonsi/si_shader_aco.c
@@ -309,7 +309,7 @@ si_aco_build_ps_epilog(struct aco_compiler_options *options,
       .spi_shader_col_format = key->ps_epilog.states.spi_shader_col_format,
       .color_is_int8 = key->ps_epilog.states.color_is_int8,
       .color_is_int10 = key->ps_epilog.states.color_is_int10,
-      .broadcast_last_cbuf = key->ps_epilog.states.last_cbuf,
+      .writes_all_cbufs = key->ps_epilog.states.last_cbuf != 0,
       .alpha_func = key->ps_epilog.states.alpha_func,
       .alpha_to_one = key->ps_epilog.states.alpha_to_one,
       .alpha_to_coverage_via_mrtz = key->ps_epilog.states.alpha_to_coverage_via_mrtz,