diff --git a/src/asahi/compiler/agx_compile.c b/src/asahi/compiler/agx_compile.c
index abf12e4ca54..fa3c839e734 100644
--- a/src/asahi/compiler/agx_compile.c
+++ b/src/asahi/compiler/agx_compile.c
@@ -891,6 +891,8 @@ agx_emit_intrinsic(agx_builder *b, nir_intrinsic_instr *instr)
          b, dst, instr, AGX_SR_THREAD_POSITION_IN_THREADGROUP_X);
 
    case nir_intrinsic_scoped_barrier: {
+      assert(!b->shader->is_preamble && "invalid");
+
       bool needs_threadgroup_barrier = false;
 
       if (nir_intrinsic_execution_scope(instr) != SCOPE_NONE) {
@@ -2164,6 +2166,7 @@ agx_compile_function_nir(nir_shader *nir, nir_function_impl *impl,
 
    agx_context *ctx = rzalloc(NULL, agx_context);
    ctx->nir = nir;
+   ctx->is_preamble = impl->function->is_preamble;
    ctx->out = out;
    ctx->key = key;
    ctx->stage = nir->info.stage;
diff --git a/src/asahi/compiler/agx_compiler.h b/src/asahi/compiler/agx_compiler.h
index e153ceb9337..d92a8f41501 100644
--- a/src/asahi/compiler/agx_compiler.h
+++ b/src/asahi/compiler/agx_compiler.h
@@ -378,6 +378,8 @@ typedef struct agx_block {
 typedef struct {
    nir_shader *nir;
    gl_shader_stage stage;
+   bool is_preamble;
+
    struct list_head blocks; /* list of agx_block */
    struct agx_shader_info *out;
    struct agx_shader_key *key;