diff --git a/oauth2.go b/oauth2.go
index de52304..9085fab 100644
--- a/oauth2.go
+++ b/oauth2.go
@@ -16,6 +16,7 @@ import (
 	"net/url"
 	"strings"
 	"sync"
+	"time"
 
 	"golang.org/x/oauth2/internal"
 )
@@ -290,6 +291,8 @@ type reuseTokenSource struct {
 
 	mu sync.Mutex // guards t
 	t  *Token
+
+	expiryDelta time.Duration
 }
 
 // Token returns the current token if it's still valid, else will
@@ -305,6 +308,7 @@ func (s *reuseTokenSource) Token() (*Token, error) {
 	if err != nil {
 		return nil, err
 	}
+	t.expiryDelta = s.expiryDelta
 	s.t = t
 	return t, nil
 }
@@ -379,3 +383,30 @@ func ReuseTokenSource(t *Token, src TokenSource) TokenSource {
 		new: src,
 	}
 }
+
+// ReuseTokenSource returns a TokenSource that acts in the same manner as the
+// TokenSource returned by ReuseTokenSource, except the expiry buffer is
+// configurable. The expiration time of a token is calculated as
+// t.Expiry.Add(-earlyExpiry).
+func ReuseTokenSourceWithExpiry(t *Token, src TokenSource, earlyExpiry time.Duration) TokenSource {
+	// Don't wrap a reuseTokenSource in itself. That would work,
+	// but cause an unnecessary number of mutex operations.
+	// Just build the equivalent one.
+	if rt, ok := src.(*reuseTokenSource); ok {
+		if t == nil {
+			// Just use it directly, but set the expiryDelta to earlyExpiry,
+			// so the behavior matches what the user expects.
+			rt.expiryDelta = earlyExpiry
+			return rt
+		}
+		src = rt.new
+	}
+	if t != nil {
+		t.expiryDelta = earlyExpiry
+	}
+	return &reuseTokenSource{
+		t:           t,
+		new:         src,
+		expiryDelta: earlyExpiry,
+	}
+}
diff --git a/token.go b/token.go
index 8227203..7c64006 100644
--- a/token.go
+++ b/token.go
@@ -16,10 +16,10 @@ import (
 	"golang.org/x/oauth2/internal"
 )
 
-// expiryDelta determines how earlier a token should be considered
+// defaultExpiryDelta determines how earlier a token should be considered
 // expired than its actual expiration time. It is used to avoid late
 // expirations due to client-server time mismatches.
-const expiryDelta = 10 * time.Second
+const defaultExpiryDelta = 10 * time.Second
 
 // Token represents the credentials used to authorize
 // the requests to access protected resources on the OAuth 2.0
@@ -52,6 +52,11 @@ type Token struct {
 	// raw optionally contains extra metadata from the server
 	// when updating a token.
 	raw interface{}
+
+	// expiryDelta is used to calculate when a token is considered
+	// expired, by subtracting from Expiry. If zero, defaultExpiryDelta
+	// is used.
+	expiryDelta time.Duration
 }
 
 // Type returns t.TokenType if non-empty, else "Bearer".
@@ -127,6 +132,11 @@ func (t *Token) expired() bool {
 	if t.Expiry.IsZero() {
 		return false
 	}
+
+	expiryDelta := defaultExpiryDelta
+	if t.expiryDelta != 0 {
+		expiryDelta = t.expiryDelta
+	}
 	return t.Expiry.Round(0).Add(-expiryDelta).Before(timeNow())
 }
 
diff --git a/token_test.go b/token_test.go
index ee97b4f..0d8c7df 100644
--- a/token_test.go
+++ b/token_test.go
@@ -43,9 +43,13 @@ func TestTokenExpiry(t *testing.T) {
 		want bool
 	}{
 		{name: "12 seconds", tok: &Token{Expiry: now.Add(12 * time.Second)}, want: false},
-		{name: "10 seconds", tok: &Token{Expiry: now.Add(expiryDelta)}, want: false},
-		{name: "10 seconds-1ns", tok: &Token{Expiry: now.Add(expiryDelta - 1*time.Nanosecond)}, want: true},
+		{name: "10 seconds", tok: &Token{Expiry: now.Add(defaultExpiryDelta)}, want: false},
+		{name: "10 seconds-1ns", tok: &Token{Expiry: now.Add(defaultExpiryDelta - 1*time.Nanosecond)}, want: true},
 		{name: "-1 hour", tok: &Token{Expiry: now.Add(-1 * time.Hour)}, want: true},
+		{name: "12 seconds, custom expiryDelta", tok: &Token{Expiry: now.Add(12 * time.Second), expiryDelta: time.Second * 5}, want: false},
+		{name: "5 seconds, custom expiryDelta", tok: &Token{Expiry: now.Add(time.Second * 5), expiryDelta: time.Second * 5}, want: false},
+		{name: "5 seconds-1ns, custom expiryDelta", tok: &Token{Expiry: now.Add(time.Second*5 - 1*time.Nanosecond), expiryDelta: time.Second * 5}, want: true},
+		{name: "-1 hour, custom expiryDelta", tok: &Token{Expiry: now.Add(-1 * time.Hour), expiryDelta: time.Second * 5}, want: true},
 	}
 	for _, tc := range cases {
 		if got, want := tc.tok.expired(), tc.want; got != want {