diff --git a/src/gallium/auxiliary/util/u_threaded_context.c b/src/gallium/auxiliary/util/u_threaded_context.c
index 5ec2851f002..08886de9d79 100644
--- a/src/gallium/auxiliary/util/u_threaded_context.c
+++ b/src/gallium/auxiliary/util/u_threaded_context.c
@@ -5452,6 +5452,9 @@ threaded_context_create(struct pipe_context *pipe,
       return NULL;
    }
 
+   /* drivers must set this */
+   assert(pipe->screen->caps.prefer_real_buffer_in_constbuf0);
+
    if (options) {
       /* this is unimplementable */
       assert(!(options->parse_renderpass_info && options->driver_calls_flush_notify));
diff --git a/src/gallium/drivers/crocus/crocus_screen.c b/src/gallium/drivers/crocus/crocus_screen.c
index 24c18b2a56f..556c2034796 100644
--- a/src/gallium/drivers/crocus/crocus_screen.c
+++ b/src/gallium/drivers/crocus/crocus_screen.c
@@ -235,6 +235,7 @@ crocus_init_screen_caps(struct crocus_screen *screen)
 
    u_init_pipe_screen_caps(&screen->base, 1);
 
+   caps->prefer_real_buffer_in_constbuf0 = true;
    caps->npot_textures = true;
    caps->anisotropic_filter = true;
    caps->occlusion_query = true;
diff --git a/src/gallium/drivers/d3d12/d3d12_screen.cpp b/src/gallium/drivers/d3d12/d3d12_screen.cpp
index 82669a18077..b83582de22e 100644
--- a/src/gallium/drivers/d3d12/d3d12_screen.cpp
+++ b/src/gallium/drivers/d3d12/d3d12_screen.cpp
@@ -232,6 +232,7 @@ d3d12_init_screen_caps(struct d3d12_screen *screen)
 
    u_init_pipe_screen_caps(&screen->base, caps->accelerated);
 
+   caps->prefer_real_buffer_in_constbuf0 = true;
    caps->npot_textures = true;
 
    /* D3D12 only supports dual-source blending for a single
diff --git a/src/gallium/drivers/freedreno/freedreno_screen.c b/src/gallium/drivers/freedreno/freedreno_screen.c
index 1e09a44a829..adffb9e93bb 100644
--- a/src/gallium/drivers/freedreno/freedreno_screen.c
+++ b/src/gallium/drivers/freedreno/freedreno_screen.c
@@ -365,6 +365,7 @@ fd_init_screen_caps(struct fd_screen *screen)
    /* this is probably not totally correct.. but it's a start: */
 
    /* Supported features (boolean caps). */
+   caps->prefer_real_buffer_in_constbuf0 = true;
    caps->npot_textures = true;
    caps->mixed_framebuffer_sizes = true;
    caps->anisotropic_filter = true;
diff --git a/src/gallium/drivers/iris/iris_screen.c b/src/gallium/drivers/iris/iris_screen.c
index 2e827533fe7..59d1fdb2672 100644
--- a/src/gallium/drivers/iris/iris_screen.c
+++ b/src/gallium/drivers/iris/iris_screen.c
@@ -285,6 +285,7 @@ iris_init_screen_caps(struct iris_screen *screen)
 
    const struct intel_device_info *devinfo = screen->devinfo;
 
+   caps->prefer_real_buffer_in_constbuf0 = true;
    caps->npot_textures = true;
    caps->anisotropic_filter = true;
    caps->occlusion_query = true;
diff --git a/src/gallium/drivers/r600/r600_pipe.c b/src/gallium/drivers/r600/r600_pipe.c
index 6f8bd868957..d09eabdec13 100644
--- a/src/gallium/drivers/r600/r600_pipe.c
+++ b/src/gallium/drivers/r600/r600_pipe.c
@@ -404,6 +404,7 @@ static void r600_init_screen_caps(struct r600_screen *rscreen)
 	enum radeon_family family = rscreen->b.family;
 
 	/* Supported features (boolean caps). */
+	caps->prefer_real_buffer_in_constbuf0 = true;
 	caps->npot_textures = true;
 	caps->mixed_framebuffer_sizes = true;
 	caps->mixed_color_depth_bits = true;