diff --git a/src/database/sql/sql.go b/src/database/sql/sql.go
index 3d957e1450..1cc1687604 100644
--- a/src/database/sql/sql.go
+++ b/src/database/sql/sql.go
@@ -8,7 +8,10 @@
 // The sql package must be used in conjunction with a database driver.
 // See https://golang.org/s/sqldrivers for a list of drivers.
 //
-// For more usage examples, see the wiki page at
+// Drivers that do not support context cancelation will not return until
+// after the query is completed.
+//
+// For usage examples, see the wiki page at
 // https://golang.org/s/sqlwiki.
 package sql