diff --git a/unix/linux/types.go b/unix/linux/types.go
index 3a564a10..67145333 100644
--- a/unix/linux/types.go
+++ b/unix/linux/types.go
@@ -1115,6 +1115,7 @@ const (
 	PerfBitCommExec                      = CBitFieldMaskBit24
 	PerfBitUseClockID                    = CBitFieldMaskBit25
 	PerfBitContextSwitch                 = CBitFieldMaskBit26
+	PerfBitWriteBackward                 = CBitFieldMaskBit27
 )
 
 // generated by:
diff --git a/unix/ztypes_linux.go b/unix/ztypes_linux.go
index 65155b3a..ca84727c 100644
--- a/unix/ztypes_linux.go
+++ b/unix/ztypes_linux.go
@@ -1067,6 +1067,7 @@ const (
 	PerfBitCommExec                      = CBitFieldMaskBit24
 	PerfBitUseClockID                    = CBitFieldMaskBit25
 	PerfBitContextSwitch                 = CBitFieldMaskBit26
+	PerfBitWriteBackward                 = CBitFieldMaskBit27
 )
 
 const (