diff --git a/documentation/configuration/cairo-engine.md b/documentation/configuration/cairo-engine.md
index 7112f46b6..bde06b951 100644
--- a/documentation/configuration/cairo-engine.md
+++ b/documentation/configuration/cairo-engine.md
@@ -58,6 +58,10 @@ available via the HTTP header
 [`options`](/docs/query/pgwire/overview/)
 connection property.
 
+The related `query.timeout` key sets the same global timeout using a duration
+value (for example, `120s`, `1m` or `500ms`). When both are set, `query.timeout`
+takes precedence over `query.timeout.sec`.
+
 ## Commit and write behavior
 
 ### cairo.commit.mode