diff --git a/src/flag/flag.go b/src/flag/flag.go
index a1a8dc7fad..5544a25282 100644
--- a/src/flag/flag.go
+++ b/src/flag/flag.go
@@ -71,6 +71,7 @@ import (
 	"reflect"
 	"sort"
 	"strconv"
+	"strings"
 	"time"
 )
 
@@ -448,9 +449,9 @@ func UnquoteUsage(flag *Flag) (name string, usage string) {
 	return
 }
 
-// PrintDefaults prints to standard error the default values of all
-// defined command-line flags in the set. See the documentation for
-// the global function PrintDefaults for more information.
+// PrintDefaults prints, to standard error unless configured otherwise, the
+// default values of all defined command-line flags in the set. See the
+// documentation for the global function PrintDefaults for more information.
 func (f *FlagSet) PrintDefaults() {
 	f.VisitAll(func(flag *Flag) {
 		s := fmt.Sprintf("  -%s", flag.Name) // Two spaces before -; see next two comments.
@@ -467,7 +468,8 @@ func (f *FlagSet) PrintDefaults() {
 			// for both 4- and 8-space tab stops.
 			s += "\n    \t"
 		}
-		s += usage
+		s += strings.Replace(usage, "\n", "\n    \t", -1)
+
 		if !isZeroValue(flag, flag.DefValue) {
 			if _, ok := flag.Value.(*stringValue); ok {
 				// put quotes on the value
diff --git a/src/flag/flag_test.go b/src/flag/flag_test.go
index 20d09c4c41..4c6db96ba0 100644
--- a/src/flag/flag_test.go
+++ b/src/flag/flag_test.go
@@ -389,8 +389,14 @@ const defaultOutput = `  -A	for bootstrapping, allow 'any' type
     	a non-zero number (default 2.7)
   -G float
     	a float that defaults to zero
+  -M string
+    	a multiline
+    	help
+    	string
   -N int
     	a non-zero int (default 27)
+  -O	a flag
+    	multiline help string (default true)
   -Z int
     	an int that defaults to zero
   -maxT timeout
@@ -407,7 +413,9 @@ func TestPrintDefaults(t *testing.T) {
 	fs.String("D", "", "set relative `path` for local imports")
 	fs.Float64("F", 2.7, "a non-zero `number`")
 	fs.Float64("G", 0, "a float that defaults to zero")
+	fs.String("M", "", "a multiline\nhelp\nstring")
 	fs.Int("N", 27, "a non-zero int")
+	fs.Bool("O", true, "a flag\nmultiline help string")
 	fs.Int("Z", 0, "an int that defaults to zero")
 	fs.Duration("maxT", 0, "set `timeout` for dial")
 	fs.PrintDefaults()