diff --git a/src/cmd/compile/internal/types2/conversions.go b/src/cmd/compile/internal/types2/conversions.go
index 51be50e..30201e2 100644
--- a/src/cmd/compile/internal/types2/conversions.go
+++ b/src/cmd/compile/internal/types2/conversions.go
@@ -38,8 +38,10 @@
 	}
 
 	if !ok {
-		check.errorf(x, "cannot convert %s to %s", x, T)
-		x.mode = invalid
+		if x.mode != invalid {
+			check.errorf(x, "cannot convert %s to %s", x, T)
+			x.mode = invalid
+		}
 		return
 	}
 
@@ -141,7 +143,16 @@
 		if p := asPointer(T); p != nil {
 			if a := asArray(p.Elem()); a != nil {
 				if check.identical(s.Elem(), a.Elem()) {
-					return true
+					if check == nil || check.allowVersion(check.pkg, 1, 17) {
+						return true
+					}
+					// check != nil
+					if check.conf.CompilerErrorMessages {
+						check.error(x, "conversion of slices to array pointers only supported as of -lang=go1.17")
+					} else {
+						check.error(x, "conversion of slices to array pointers requires go1.17 or later")
+					}
+					x.mode = invalid // avoid follow-up error
 				}
 			}
 		}
diff --git a/src/cmd/compile/internal/types2/decl.go b/src/cmd/compile/internal/types2/decl.go
index 4966f19..1333e4c 100644
--- a/src/cmd/compile/internal/types2/decl.go
+++ b/src/cmd/compile/internal/types2/decl.go
@@ -601,7 +601,7 @@
 
 	if alias {
 		// type alias declaration
-		if !check.allowVersion(obj.pkg, 1, 9) {
+		if !check.allowVersion(check.pkg, 1, 9) {
 			if check.conf.CompilerErrorMessages {
 				check.error(tdecl, "type aliases only supported as of -lang=go1.9")
 			} else {
diff --git a/src/cmd/compile/internal/types2/testdata/check/go1_16.src b/src/cmd/compile/internal/types2/testdata/check/go1_16.src
new file mode 100644
index 0000000..fdf5c99
--- /dev/null
+++ b/src/cmd/compile/internal/types2/testdata/check/go1_16.src
@@ -0,0 +1,13 @@
+// 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.
+
+// Check Go language version-specific errors.
+
+package go1_16 // go1.16
+
+type Slice []byte
+type Array [8]byte
+
+var s Slice
+var p = (*Array)(s /* ERROR requires go1.17 or later */ )