diff --git a/doc/xml/reference.xml b/doc/xml/reference.xml
index cc4ff3b46..a553bc0d5 100644
--- a/doc/xml/reference.xml
+++ b/doc/xml/reference.xml
@@ -192,7 +192,7 @@
                     <config-key id="io-timeout" name="I/O Timeout">
                         <summary>I/O timeout.</summary>
 
-                        <text>Timeout used for connections and read/write operations.
+                        <text>Timeout, in seconds, used for connections and read/write operations.
 
                         Note that the entire read/write operation does not need to complete within this timeout but <i>some</i> progress must be made, even if it is only a single byte.</text>
 
diff --git a/src/config/define.auto.c b/src/config/define.auto.c
index c61efabf6..12ee8e255 100644
--- a/src/config/define.auto.c
+++ b/src/config/define.auto.c
@@ -1393,7 +1393,7 @@ static ConfigDefineOptionData configDefineOptionData[] = CFGDEFDATA_OPTION_LIST
         CFGDEFDATA_OPTION_HELP_SUMMARY("I/O timeout.")
         CFGDEFDATA_OPTION_HELP_DESCRIPTION
         (
-            "Timeout used for connections and read/write operations.\n"
+            "Timeout, in seconds, used for connections and read/write operations.\n"
             "\n"
             "Note that the entire read/write operation does not need to complete within this timeout but some progress must be "
                 "made, even if it is only a single byte."