diff --git a/system-variables.md b/system-variables.md
index 0fd1f8c344b3d..f6c35e422d205 100644
--- a/system-variables.md
+++ b/system-variables.md
@@ -3106,7 +3106,7 @@ For a system upgraded to v5.0 from an earlier version, if you have not modified
 - Default value: `-1`
 - Range: `[-1, 256]`
 - Unit: Threads
-- This variable is used to set the maximum concurrency for TiFlash to execute a request. The default value is `-1`, indicating that this system variable is invalid. When the value is `0`, the maximum number of threads is automatically configured by TiFlash.
+- This variable is used to set the maximum concurrency for TiFlash to execute a request. The default value is `-1`, indicating that this system variable is invalid and the maximum concurrency depends on the setting of the TiFlash configuration `profiles.default.max_threads`. When the value is `0`, the maximum number of threads is automatically configured by TiFlash.
 
 ### tidb_mem_oom_action <span class="version-mark">New in v6.1.0</span>