diff --git a/Documentation/config.txt b/Documentation/config.txt
index 5319df5..5ffd141 100644
--- a/Documentation/config.txt
+++ b/Documentation/config.txt
@@ -61,7 +61,7 @@
 
 The values following the equals sign in variable assign are all either
 a string, an integer, or a boolean.  Boolean values may be given as yes/no,
-0/1 or true/false.  Case is not significant in boolean values, when
+0/1, true/false or on/off.  Case is not significant in boolean values, when
 converting value to the canonical form using '--bool' type specifier;
 'git-config' will ensure that the output is "true" or "false".
 
diff --git a/config.c b/config.c
index 2d70398..8c1ae59 100644
--- a/config.c
+++ b/config.c
@@ -331,9 +331,9 @@
 		return 1;
 	if (!*value)
 		return 0;
-	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes"))
+	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 		return 1;
-	if (!strcasecmp(value, "false") || !strcasecmp(value, "no"))
+	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 		return 0;
 	*is_bool = 0;
 	return git_config_int(name, value);