diff --git a/src/go/types/call.go b/src/go/types/call.go
index 631ea426c6..3a04121e98 100644
--- a/src/go/types/call.go
+++ b/src/go/types/call.go
@@ -575,17 +575,38 @@ func (check *Checker) selector(x *operand, e *ast.SelectorExpr) {
 
 		check.recordSelection(e, MethodExpr, x.typ, m, index, indirect)
 
+		sig := m.typ.(*Signature)
+		if sig.recv == nil {
+			check.error(e, _InvalidDeclCycle, "illegal cycle in method declaration")
+			goto Error
+		}
+
 		// the receiver type becomes the type of the first function
 		// argument of the method expression's function type
 		var params []*Var
-		sig := m.typ.(*Signature)
 		if sig.params != nil {
 			params = sig.params.vars
 		}
+		// Be consistent about named/unnamed parameters.
+		needName := true
+		for _, param := range params {
+			if param.Name() == "" {
+				needName = false
+				break
+			}
+		}
+		name := ""
+		if needName {
+			name = sig.recv.name
+			if name == "" {
+				name = "_"
+			}
+		}
+		params = append([]*Var{NewVar(sig.recv.pos, sig.recv.pkg, name, x.typ)}, params...)
 		x.mode = value
 		x.typ = &Signature{
 			tparams:  sig.tparams,
-			params:   NewTuple(append([]*Var{NewVar(token.NoPos, check.pkg, "_", x.typ)}, params...)...),
+			params:   NewTuple(params...),
 			results:  sig.results,
 			variadic: sig.variadic,
 		}
diff --git a/src/go/types/testdata/check/decls0.src b/src/go/types/testdata/check/decls0.src
index 5ad8f53f65..09904bb303 100644
--- a/src/go/types/testdata/check/decls0.src
+++ b/src/go/types/testdata/check/decls0.src
@@ -187,10 +187,10 @@ func f4() (x *f4 /* ERROR "not a type" */ ) { return }
 // TODO(#43215) this should be detected as a cycle error
 func f5([unsafe.Sizeof(f5)]int) {}
 
-func (S0) m1 (x S0 /* ERROR value .* is not a type */ .m1) {}
-func (S0) m2 (x *S0 /* ERROR value .* is not a type */ .m2) {}
-func (S0) m3 () (x S0 /* ERROR value .* is not a type */ .m3) { return }
-func (S0) m4 () (x *S0 /* ERROR value .* is not a type */ .m4) { return }
+func (S0) m1 (x S0 /* ERROR illegal cycle in method declaration */ .m1) {}
+func (S0) m2 (x *S0 /* ERROR illegal cycle in method declaration */ .m2) {}
+func (S0) m3 () (x S0 /* ERROR illegal cycle in method declaration */ .m3) { return }
+func (S0) m4 () (x *S0 /* ERROR illegal cycle in method declaration */ .m4) { return }
 
 // interfaces may not have any blank methods
 type BlankI interface {