diff --git a/src/gallium/drivers/zink/nir_to_spirv/spirv_builder.c b/src/gallium/drivers/zink/nir_to_spirv/spirv_builder.c
index a413c551d06..1254f4cd19b 100644
--- a/src/gallium/drivers/zink/nir_to_spirv/spirv_builder.c
+++ b/src/gallium/drivers/zink/nir_to_spirv/spirv_builder.c
@@ -1086,6 +1086,17 @@ spirv_builder_type_matrix(struct spirv_builder *b, SpvId component_type,
    return get_type_def(b, SpvOpTypeMatrix, args, ARRAY_SIZE(args));
 }
 
+SpvId
+spirv_builder_type_runtime_array(struct spirv_builder *b, SpvId component_type)
+{
+   SpvId type = spirv_builder_new_id(b);
+   spirv_buffer_prepare(&b->types_const_defs, b->mem_ctx, 3);
+   spirv_buffer_emit_word(&b->types_const_defs, SpvOpTypeRuntimeArray | (3 << 16));
+   spirv_buffer_emit_word(&b->types_const_defs, type);
+   spirv_buffer_emit_word(&b->types_const_defs, component_type);
+   return type;
+}
+
 SpvId
 spirv_builder_type_array(struct spirv_builder *b, SpvId component_type,
                          SpvId length)
diff --git a/src/gallium/drivers/zink/nir_to_spirv/spirv_builder.h b/src/gallium/drivers/zink/nir_to_spirv/spirv_builder.h
index 632f196733f..6f0281212a7 100644
--- a/src/gallium/drivers/zink/nir_to_spirv/spirv_builder.h
+++ b/src/gallium/drivers/zink/nir_to_spirv/spirv_builder.h
@@ -336,6 +336,9 @@ SpvId
 spirv_builder_type_matrix(struct spirv_builder *b, SpvId component_type,
                           unsigned component_count);
 
+SpvId
+spirv_builder_type_runtime_array(struct spirv_builder *b, SpvId component_type);
+
 SpvId
 spirv_builder_type_array(struct spirv_builder *b, SpvId component_type,
                          SpvId length);