diff --git a/src/cmd/compile/internal/noder/stencil.go b/src/cmd/compile/internal/noder/stencil.go
index 6736f128e3..4ac37c362c 100644
--- a/src/cmd/compile/internal/noder/stencil.go
+++ b/src/cmd/compile/internal/noder/stencil.go
@@ -1224,6 +1224,11 @@ func convertUsingDictionary(info *instInfo, dictParam *ir.Name, pos src.XPos, v
 		}
 		assert(ix >= 0)
 		rt = getDictionaryEntry(pos, dictParam, ix, info.dictLen)
+	} else if v.Type().IsInterface() {
+		ta := ir.NewTypeAssertExpr(pos, v, nil)
+		ta.SetType(dst)
+		ta.SetTypecheck(1)
+		return ta
 	} else {
 		ix := findDictType(info, src)
 		assert(ix >= 0)
diff --git a/test/typeparam/issue47272.go b/test/typeparam/issue47272.go
new file mode 100644
index 0000000000..6771cb9901
--- /dev/null
+++ b/test/typeparam/issue47272.go
@@ -0,0 +1,55 @@
+// run -gcflags=-G=3
+
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"errors"
+	"fmt"
+)
+
+type Option[T any] struct {
+	ok  bool
+	val T
+}
+
+func (o Option[T]) String() string {
+	if o.ok {
+		return fmt.Sprintf("Some(%v)", o.val)
+	}
+	return "None"
+}
+
+func Some[T any](val T) Option[T] { return Option[T]{ok: true, val: val} }
+func None[T any]() Option[T]      { return Option[T]{ok: false} }
+
+type Result[T, E any] struct {
+	ok  bool
+	val T
+	err E
+}
+
+func (r Result[T, E]) String() string {
+	if r.ok {
+		return fmt.Sprintf("Ok(%v)", r.val)
+	}
+	return fmt.Sprintf("Err(%v)", r.err)
+}
+
+func Ok[T, E any](val T) Result[T, E]  { return Result[T, E]{ok: true, val: val} }
+func Err[T, E any](err E) Result[T, E] { return Result[T, E]{ok: false, err: err} }
+
+func main() {
+	a := Some[int](1)
+	b := None[int]()
+	fmt.Println(a, b)
+
+	x := Ok[int, error](1)
+	y := Err[int, error](errors.New("test"))
+	fmt.Println(x, y)
+	// fmt.Println(x)
+	_, _, _, _ = a, b, x, y
+}
diff --git a/test/typeparam/issue47272.out b/test/typeparam/issue47272.out
new file mode 100644
index 0000000000..9c433faa97
--- /dev/null
+++ b/test/typeparam/issue47272.out
@@ -0,0 +1,2 @@
+Some(1) None
+Ok(1) Err(test)