diff --git a/go/ast/astutil/rewrite.go b/go/ast/astutil/rewrite.go
index 729e9c8..f430b21 100644
--- a/go/ast/astutil/rewrite.go
+++ b/go/ast/astutil/rewrite.go
@@ -293,6 +293,9 @@
 		a.apply(n, "Fields", nil, n.Fields)
 
 	case *ast.FuncType:
+		if tparams := typeparams.ForFuncType(n); tparams != nil {
+			a.apply(n, "TypeParams", nil, tparams)
+		}
 		a.apply(n, "Params", nil, n.Params)
 		a.apply(n, "Results", nil, n.Results)
 
@@ -405,6 +408,9 @@
 	case *ast.TypeSpec:
 		a.apply(n, "Doc", nil, n.Doc)
 		a.apply(n, "Name", nil, n.Name)
+		if tparams := typeparams.ForTypeSpec(n); tparams != nil {
+			a.apply(n, "TypeParams", nil, tparams)
+		}
 		a.apply(n, "Type", nil, n.Type)
 		a.apply(n, "Comment", nil, n.Comment)
 
diff --git a/go/ast/astutil/rewrite_test.go b/go/ast/astutil/rewrite_test.go
index 9d23170..4ef6fe9 100644
--- a/go/ast/astutil/rewrite_test.go
+++ b/go/ast/astutil/rewrite_test.go
@@ -202,20 +202,30 @@
 type T[P1, P2 any] int
 
 type R T[int, string]
+
+func F[Q1 any](q Q1) {}
 `,
+			// TODO: note how the rewrite adds a trailing comma in "func F".
+			// Is that a bug in the test, or in astutil.Apply?
 			want: `package p
 
-type S[P1, P2 any] int32
+type S[R1, P2 any] int32
 
 type R S[int32, string]
+
+func F[X1 any](q X1,) {}
 `,
 			post: func(c *astutil.Cursor) bool {
 				if ident, ok := c.Node().(*ast.Ident); ok {
-					if ident.Name == "int" {
+					switch ident.Name {
+					case "int":
 						c.Replace(ast.NewIdent("int32"))
-					}
-					if ident.Name == "T" {
+					case "T":
 						c.Replace(ast.NewIdent("S"))
+					case "P1":
+						c.Replace(ast.NewIdent("R1"))
+					case "Q1":
+						c.Replace(ast.NewIdent("X1"))
 					}
 				}
 				return true