diff --git a/src/cmd/compile/internal/types2/resolver.go b/src/cmd/compile/internal/types2/resolver.go
index 2c98ca20e30..7ea9bde5fad 100644
--- a/src/cmd/compile/internal/types2/resolver.go
+++ b/src/cmd/compile/internal/types2/resolver.go
@@ -397,15 +397,16 @@ func (check *Checker) collectObjects() {
 				obj := NewFunc(d.Name.Pos(), pkg, name, nil)
 				if d.Recv == nil {
 					// regular function
-					if name == "init" {
+					if name == "init" || name == "main" && pkg.name == "main" {
 						if d.TParamList != nil {
-							//check.softErrorf(d.TParamList.Pos(), "func init must have no type parameters")
-							check.softErrorf(d.Name, "func init must have no type parameters")
+							check.softErrorf(d, "func %s must have no type parameters", name)
 						}
 						if t := d.Type; len(t.ParamList) != 0 || len(t.ResultList) != 0 {
-							check.softErrorf(d, "func init must have no arguments and no return values")
+							check.softErrorf(d, "func %s must have no arguments and no return values", name)
 						}
-						// don't declare init functions in the package scope - they are invisible
+					}
+					// don't declare init functions in the package scope - they are invisible
+					if name == "init" {
 						obj.parent = pkg.scope
 						check.recordDef(d.Name, obj)
 						// init functions must have a body
diff --git a/src/cmd/compile/internal/types2/testdata/main.go2 b/src/cmd/compile/internal/types2/testdata/main.go2
new file mode 100644
index 00000000000..b7ddeaa1a88
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/main.go2
@@ -0,0 +1,7 @@
+// Copyright 2020 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
+
+func /* ERROR "func main must have no type parameters" */ main[T any]() {}
diff --git a/src/cmd/compile/internal/types2/testdata/main.src b/src/cmd/compile/internal/types2/testdata/main.src
new file mode 100644
index 00000000000..f892938d4ac
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/main.src
@@ -0,0 +1,9 @@
+// Copyright 2020 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
+
+func main()
+func /* ERROR "no arguments and no return values" */ main /* ERROR redeclared */ (int)
+func /* ERROR "no arguments and no return values" */ main /* ERROR redeclared */ () int
diff --git a/test/run.go b/test/run.go
index 5ec33f16f20..fcf8a4fcc96 100644
--- a/test/run.go
+++ b/test/run.go
@@ -1936,7 +1936,6 @@ var excluded = map[string]bool{
 	"import6.go":      true, // issue #43109
 	"initializerr.go": true, // types2 reports extra errors
 	"linkname2.go":    true, // error reported by noder (not running for types2 errorcheck test)
-	"mainsig.go":      true, // issue #43308
 	"shift1.go":       true, // issue #42989
 	"switch4.go":      true, // error reported by noder (not running for types2 errorcheck test)
 	"typecheck.go":    true, // invalid function is not causing errors when called