diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
index 26fb337f86..94a9dcb983 100644
--- a/src/cmd/go/alldocs.go
+++ b/src/cmd/go/alldocs.go
@@ -2579,7 +2579,9 @@
 // The go command can fetch modules from a proxy or connect to source control
 // servers directly, according to the setting of the GOPROXY environment
 // variable (see 'go help env'). The default setting for GOPROXY is
-// "https://proxy.golang.org", the Go module mirror run by Google.
+// "https://proxy.golang.org,direct", which means to try the
+// Go module mirror run by Google and fall back to a direct connection
+// if the proxy reports that it does not have the module (HTTP error 404 or 410).
 // See https://proxy.golang.org/privacy for the service's privacy policy.
 // If GOPROXY is set to the string "direct", downloads use a direct connection
 // to source control servers. Setting GOPROXY to "off" disallows downloading
diff --git a/src/cmd/go/internal/modload/help.go b/src/cmd/go/internal/modload/help.go
index 96fec8451e..cb996d3546 100644
--- a/src/cmd/go/internal/modload/help.go
+++ b/src/cmd/go/internal/modload/help.go
@@ -331,7 +331,9 @@ Module downloading and verification
 The go command can fetch modules from a proxy or connect to source control
 servers directly, according to the setting of the GOPROXY environment
 variable (see 'go help env'). The default setting for GOPROXY is
-"https://proxy.golang.org", the Go module mirror run by Google.
+"https://proxy.golang.org,direct", which means to try the
+Go module mirror run by Google and fall back to a direct connection
+if the proxy reports that it does not have the module (HTTP error 404 or 410).
 See https://proxy.golang.org/privacy for the service's privacy policy.
 If GOPROXY is set to the string "direct", downloads use a direct connection
 to source control servers. Setting GOPROXY to "off" disallows downloading