diff --git a/src/asahi/lib/agx_nir_lower_sample_intrinsics.c b/src/asahi/lib/agx_nir_lower_sample_intrinsics.c
index 58a0ef31a68..8ff1e4d3fac 100644
--- a/src/asahi/lib/agx_nir_lower_sample_intrinsics.c
+++ b/src/asahi/lib/agx_nir_lower_sample_intrinsics.c
@@ -20,7 +20,7 @@ select_if_msaa_else_0(nir_builder *b, nir_def *x)
 }
 
 static bool
-lower(nir_builder *b, nir_intrinsic_instr *intr, void *_)
+lower(nir_builder *b, nir_intrinsic_instr *intr, void *data)
 {
    b->cursor = nir_before_instr(&intr->instr);
 
@@ -145,8 +145,11 @@ lower(nir_builder *b, nir_intrinsic_instr *intr, void *_)
 
    case nir_intrinsic_store_output: {
       /*
-       * Sample mask writes are ignored unless multisampling is used. If it is
-       * used, the Vulkan spec says:
+       * In OpenGL, sample mask writes are ignored unless multisampling is used.
+       * This is not the case in Vulkan, disambiguated by the
+       * ignore_sample_mask_without_msaa flag.
+       *
+       * If it is used, the Vulkan spec says:
        *
        *    If sample shading is enabled, bits written to SampleMask
        *    corresponding to samples that are not being shaded by the fragment
@@ -160,8 +163,12 @@ lower(nir_builder *b, nir_intrinsic_instr *intr, void *_)
          return false;
 
       nir_def *mask = nir_inot(b, nir_u2u16(b, intr->src[0].ssa));
+      bool *ignore_sample_mask_without_msaa = data;
 
-      nir_discard_agx(b, select_if_msaa_else_0(b, mask));
+      if (*ignore_sample_mask_without_msaa)
+         mask = select_if_msaa_else_0(b, mask);
+
+      nir_discard_agx(b, mask);
       nir_instr_remove(&intr->instr);
 
       b->shader->info.fs.uses_discard = true;
@@ -187,8 +194,10 @@ lower(nir_builder *b, nir_intrinsic_instr *intr, void *_)
  * epilogs even though there's no dependency on sample count.
  */
 bool
-agx_nir_lower_sample_intrinsics(nir_shader *shader)
+agx_nir_lower_sample_intrinsics(nir_shader *shader,
+                                bool ignore_sample_mask_without_msaa)
 {
    return nir_shader_intrinsics_pass(
-      shader, lower, nir_metadata_block_index | nir_metadata_dominance, NULL);
+      shader, lower, nir_metadata_block_index | nir_metadata_dominance,
+      &ignore_sample_mask_without_msaa);
 }
diff --git a/src/asahi/lib/agx_tilebuffer.h b/src/asahi/lib/agx_tilebuffer.h
index c08d5027dad..ff2b621976f 100644
--- a/src/asahi/lib/agx_tilebuffer.h
+++ b/src/asahi/lib/agx_tilebuffer.h
@@ -100,7 +100,8 @@ bool agx_nir_lower_to_per_sample(struct nir_shader *shader);
 bool agx_nir_lower_monolithic_msaa(struct nir_shader *shader,
                                    uint8_t nr_samples);
 
-bool agx_nir_lower_sample_intrinsics(struct nir_shader *shader);
+bool agx_nir_lower_sample_intrinsics(struct nir_shader *shader,
+                                     bool ignore_sample_mask_without_msaa);
 
 bool agx_nir_lower_alpha_to_coverage(struct nir_shader *shader,
                                      uint8_t nr_samples);
diff --git a/src/gallium/drivers/asahi/agx_state.c b/src/gallium/drivers/asahi/agx_state.c
index 6e44cec40f8..423233017ec 100644
--- a/src/gallium/drivers/asahi/agx_state.c
+++ b/src/gallium/drivers/asahi/agx_state.c
@@ -1888,7 +1888,7 @@ agx_shader_initialize(struct agx_device *dev, struct agx_uncompiled_shader *so,
    }
 
    if (nir->info.stage == MESA_SHADER_FRAGMENT) {
-      NIR_PASS(_, nir, agx_nir_lower_sample_intrinsics);
+      NIR_PASS(_, nir, agx_nir_lower_sample_intrinsics, true);
    }
 
    so->type = pipe_shader_type_from_mesa(nir->info.stage);