diff --git a/src/asahi/lib/agx_device.h b/src/asahi/lib/agx_device.h
index ee4c9b86f8f..5465f48ef73 100644
--- a/src/asahi/lib/agx_device.h
+++ b/src/asahi/lib/agx_device.h
@@ -26,6 +26,7 @@ enum agx_dbg {
    AGX_DBG_RESOURCE = BITFIELD_BIT(10),
    AGX_DBG_BATCH = BITFIELD_BIT(11),
    AGX_DBG_NOWC = BITFIELD_BIT(12),
+   AGX_DBG_SYNCTVB = BITFIELD_BIT(13),
 };
 
 /* Dummy partial declarations, pending real UAPI */
diff --git a/src/gallium/drivers/asahi/agx_pipe.c b/src/gallium/drivers/asahi/agx_pipe.c
index 7b7054e40d8..eceaf893a23 100644
--- a/src/gallium/drivers/asahi/agx_pipe.c
+++ b/src/gallium/drivers/asahi/agx_pipe.c
@@ -64,6 +64,7 @@ static const struct debug_named_value agx_debug_options[] = {
    {"resource",  AGX_DBG_RESOURCE, "Log resource operations"},
    {"batch",     AGX_DBG_BATCH,    "Log batches"},
    {"nowc",      AGX_DBG_NOWC,     "Disable write-combining"},
+   {"synctvb",   AGX_DBG_SYNCTVB,  "Synchronous TVB growth"},
    DEBUG_NAMED_VALUE_END
 };
 /* clang-format on */