diff --git a/src/internal/goexperiment/exp_sizespecializedmalloc_off.go b/src/internal/goexperiment/exp_sizespecializedmalloc_off.go
new file mode 100644
index 0000000000..2642a12d79
--- /dev/null
+++ b/src/internal/goexperiment/exp_sizespecializedmalloc_off.go
@@ -0,0 +1,8 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build !goexperiment.sizespecializedmalloc
+
+package goexperiment
+
+const SizeSpecializedMalloc = false
+const SizeSpecializedMallocInt = 0
diff --git a/src/internal/goexperiment/exp_sizespecializedmalloc_on.go b/src/internal/goexperiment/exp_sizespecializedmalloc_on.go
new file mode 100644
index 0000000000..a135cc889e
--- /dev/null
+++ b/src/internal/goexperiment/exp_sizespecializedmalloc_on.go
@@ -0,0 +1,8 @@
+// Code generated by mkconsts.go. DO NOT EDIT.
+
+//go:build goexperiment.sizespecializedmalloc
+
+package goexperiment
+
+const SizeSpecializedMalloc = true
+const SizeSpecializedMallocInt = 1
diff --git a/src/internal/goexperiment/flags.go b/src/internal/goexperiment/flags.go
index 3144d3adfc..84dbf594b8 100644
--- a/src/internal/goexperiment/flags.go
+++ b/src/internal/goexperiment/flags.go
@@ -115,4 +115,7 @@ type Flags struct {
 	// RandomizedHeapBase enables heap base address randomization on 64-bit
 	// platforms.
 	RandomizedHeapBase64 bool
+
+	// SizeSpecializedMalloc enables malloc implementations that are specialized per size class.
+	SizeSpecializedMalloc bool
 }