diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
index c2678c3..ef054c8 100644
--- a/src/cmd/go/alldocs.go
+++ b/src/cmd/go/alldocs.go
@@ -1017,7 +1017,8 @@
 //
 // Download downloads the named modules, which can be module patterns selecting
 // dependencies of the main module or module queries of the form path@version.
-// With no arguments, download applies to all dependencies of the main module.
+// With no arguments, download applies to all dependencies of the main module
+// (equivalent to 'go mod download all').
 //
 // The go command will automatically download modules as needed during ordinary
 // execution. The "go mod download" command is useful mainly for pre-filling
diff --git a/src/cmd/go/internal/modcmd/download.go b/src/cmd/go/internal/modcmd/download.go
index 7d5294d..5844349 100644
--- a/src/cmd/go/internal/modcmd/download.go
+++ b/src/cmd/go/internal/modcmd/download.go
@@ -24,7 +24,8 @@
 	Long: `
 Download downloads the named modules, which can be module patterns selecting
 dependencies of the main module or module queries of the form path@version.
-With no arguments, download applies to all dependencies of the main module.
+With no arguments, download applies to all dependencies of the main module
+(equivalent to 'go mod download all').
 
 The go command will automatically download modules as needed during ordinary
 execution. The "go mod download" command is useful mainly for pre-filling