diff --git a/src/cmd/compile/internal/noder/decl.go b/src/cmd/compile/internal/noder/decl.go
index 0143fd3d45..027c8598fd 100644
--- a/src/cmd/compile/internal/noder/decl.go
+++ b/src/cmd/compile/internal/noder/decl.go
@@ -86,6 +86,7 @@ func (g *irgen) constDecl(out *ir.Nodes, decl *syntax.ConstDecl) {
 }
 
 func (g *irgen) funcDecl(out *ir.Nodes, decl *syntax.FuncDecl) {
+	assert(g.curDecl == "")
 	// Set g.curDecl to the function name, as context for the type params declared
 	// during types2-to-types1 translation if this is a generic function.
 	g.curDecl = decl.Name.Value
@@ -133,6 +134,7 @@ func (g *irgen) funcDecl(out *ir.Nodes, decl *syntax.FuncDecl) {
 	}
 
 	haveEmbed := g.haveEmbed
+	g.curDecl = ""
 	g.later(func() {
 		defer func(b bool) { g.haveEmbed = b }(g.haveEmbed)
 
@@ -158,6 +160,7 @@ func (g *irgen) funcDecl(out *ir.Nodes, decl *syntax.FuncDecl) {
 }
 
 func (g *irgen) typeDecl(out *ir.Nodes, decl *syntax.TypeDecl) {
+	assert(g.curDecl == "")
 	// Set g.curDecl to the type name, as context for the type params declared
 	// during types2-to-types1 translation if this is a generic type.
 	g.curDecl = decl.Name.Value
@@ -167,6 +170,7 @@ func (g *irgen) typeDecl(out *ir.Nodes, decl *syntax.TypeDecl) {
 		assert(name.Alias()) // should be set by irgen.obj
 
 		out.Append(ir.NewDecl(g.pos(decl), ir.ODCLTYPE, name))
+		g.curDecl = ""
 		return
 	}
 
@@ -219,6 +223,7 @@ func (g *irgen) typeDecl(out *ir.Nodes, decl *syntax.TypeDecl) {
 	}
 	types.ResumeCheckSize()
 
+	g.curDecl = ""
 	if otyp, ok := otyp.(*types2.Named); ok && otyp.NumMethods() != 0 {
 		methods := make([]*types.Field, otyp.NumMethods())
 		for i := range methods {
@@ -229,6 +234,7 @@ func (g *irgen) typeDecl(out *ir.Nodes, decl *syntax.TypeDecl) {
 			meth := g.obj(m)
 			methods[i] = types.NewField(meth.Pos(), g.selector(m), meth.Type())
 			methods[i].Nname = meth
+			g.curDecl = ""
 		}
 		ntyp.Methods().Set(methods)
 	}
diff --git a/src/cmd/compile/internal/noder/types.go b/src/cmd/compile/internal/noder/types.go
index fa24ab1844..4f6d828720 100644
--- a/src/cmd/compile/internal/noder/types.go
+++ b/src/cmd/compile/internal/noder/types.go
@@ -229,6 +229,7 @@ func (g *irgen) typ0(typ types2.Type) *types.Type {
 		pkg := g.tpkg(typ)
 		// Create the unique types1 name for a type param, using its context with a
 		// function, type, or method declaration.
+		assert(g.curDecl != "")
 		nm := g.curDecl + "." + typ.Obj().Name()
 		sym := pkg.Lookup(nm)
 		if sym.Def != nil {
@@ -331,11 +332,15 @@ func (g *irgen) fillinMethods(typ *types2.Named, ntyp *types.Type) {
 				tparams := make([]*types.Type, rparams.Len())
 				// Set g.curDecl to be the method context, so type
 				// params in the receiver of the method that we are
-				// translating gets the right unique name.
+				// translating gets the right unique name. We could
+				// be in a top-level typeDecl, so save and restore
+				// the current contents of g.curDecl.
+				savedCurDecl := g.curDecl
 				g.curDecl = typ.Obj().Name() + "." + m.Name()
 				for i := range tparams {
 					tparams[i] = g.typ1(rparams.At(i))
 				}
+				g.curDecl = savedCurDecl
 				assert(len(tparams) == len(targs))
 				ts := typecheck.Tsubster{
 					Tparams: tparams,
diff --git a/test/typeparam/issue49893.dir/a.go b/test/typeparam/issue49893.dir/a.go
new file mode 100644
index 0000000000..bc810cd3dd
--- /dev/null
+++ b/test/typeparam/issue49893.dir/a.go
@@ -0,0 +1,15 @@
+// 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 a
+
+type Option[T any] interface {
+	ToSeq() Seq[T]
+}
+
+type Seq[T any] []T
+
+func (r Seq[T]) Find(p func(v T) bool) Option[T] {
+	panic("")
+}
diff --git a/test/typeparam/issue49893.dir/b.go b/test/typeparam/issue49893.dir/b.go
new file mode 100644
index 0000000000..b36f6bddf0
--- /dev/null
+++ b/test/typeparam/issue49893.dir/b.go
@@ -0,0 +1,15 @@
+// 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 b
+
+import "a"
+
+type Ap1[A, B any] struct {
+	opt a.Option[A]
+}
+
+type Ap2[A, B any] struct {
+	opt a.Option[A]
+}
diff --git a/test/typeparam/issue49893.dir/main.go b/test/typeparam/issue49893.dir/main.go
new file mode 100644
index 0000000000..8b5b3bdad7
--- /dev/null
+++ b/test/typeparam/issue49893.dir/main.go
@@ -0,0 +1,15 @@
+// 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 (
+	"b"
+	"fmt"
+)
+
+func main() {
+	opt := b.Ap1[string, string]{}
+	fmt.Println(opt)
+}
diff --git a/test/typeparam/issue49893.go b/test/typeparam/issue49893.go
new file mode 100644
index 0000000000..87b4ff46c1
--- /dev/null
+++ b/test/typeparam/issue49893.go
@@ -0,0 +1,7 @@
+// compiledir -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 ignored