diff --git a/docs/README.md b/docs/README.md
index ee0c34d329..55e27c8d09 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -248,7 +248,7 @@ It is also safe downgrading to older versions unless [release notes](https://git
 
 The following steps must be performed during the upgrade / downgrade procedure:
 
-* Send `SIGINT` signal to VictoriaMetrics process in order to gracefully stop it.
+* Send `SIGINT` signal to VictoriaMetrics process in order to gracefully stop it. See [how to send signals to processes](https://stackoverflow.com/questions/33239959/send-signal-to-process-from-command-line).
 * Wait until the process stops. This can take a few seconds.
 * Start the upgraded VictoriaMetrics.
 
diff --git a/docs/Single-server-VictoriaMetrics.md b/docs/Single-server-VictoriaMetrics.md
index 778c489eb1..720b584749 100644
--- a/docs/Single-server-VictoriaMetrics.md
+++ b/docs/Single-server-VictoriaMetrics.md
@@ -252,7 +252,7 @@ It is also safe downgrading to older versions unless [release notes](https://git
 
 The following steps must be performed during the upgrade / downgrade procedure:
 
-* Send `SIGINT` signal to VictoriaMetrics process in order to gracefully stop it.
+* Send `SIGINT` signal to VictoriaMetrics process in order to gracefully stop it. See [how to send signals to processes](https://stackoverflow.com/questions/33239959/send-signal-to-process-from-command-line).
 * Wait until the process stops. This can take a few seconds.
 * Start the upgraded VictoriaMetrics.