diff --git a/api/go1.25.txt b/api/go1.25.txt
index cb3900bf46..d50d19545f 100644
--- a/api/go1.25.txt
+++ b/api/go1.25.txt
@@ -101,6 +101,7 @@ pkg testing, method (*F) Output() io.Writer #59928
 pkg testing, method (*T) Attr(string, string) #43936
 pkg testing, method (*T) Output() io.Writer #59928
 pkg testing, type TB interface, Attr(string, string) #43936
+pkg testing, type TB interface, Output() io.Writer #59928
 pkg testing/fstest, method (MapFS) Lstat(string) (fs.FileInfo, error) #49580
 pkg testing/fstest, method (MapFS) ReadLink(string) (string, error) #49580
 pkg testing/synctest, func Test(*testing.T, func(*testing.T)) #67434
diff --git a/src/testing/testing.go b/src/testing/testing.go
index b5305f29cc..b2d4c0c938 100644
--- a/src/testing/testing.go
+++ b/src/testing/testing.go
@@ -900,6 +900,7 @@ type TB interface {
 	Skipped() bool
 	TempDir() string
 	Context() context.Context
+	Output() io.Writer
 
 	// A private method to prevent users implementing the
 	// interface and so future additions to it will not