diff --git a/src/cmd/compile/internal/types2/under.go b/src/cmd/compile/internal/types2/under.go
index 6b24399de4..2d90c35d3b 100644
--- a/src/cmd/compile/internal/types2/under.go
+++ b/src/cmd/compile/internal/types2/under.go
@@ -22,6 +22,7 @@ func under(t Type) Type {
 // identical element types), the single underlying type is the restricted
 // channel type if the restrictions are always the same, or nil otherwise.
 func coreType(t Type) Type {
+	t = Unalias(t)
 	tpar, _ := t.(*TypeParam)
 	if tpar == nil {
 		return under(t)
@@ -51,6 +52,7 @@ func coreType(t Type) Type {
 // and strings as identical. In this case, if successful and we saw
 // a string, the result is of type (possibly untyped) string.
 func coreString(t Type) Type {
+	t = Unalias(t)
 	tpar, _ := t.(*TypeParam)
 	if tpar == nil {
 		return under(t) // string or untyped string
diff --git a/src/go/types/under.go b/src/go/types/under.go
index 9f9740e7c3..ed5aab238e 100644
--- a/src/go/types/under.go
+++ b/src/go/types/under.go
@@ -25,6 +25,7 @@ func under(t Type) Type {
 // identical element types), the single underlying type is the restricted
 // channel type if the restrictions are always the same, or nil otherwise.
 func coreType(t Type) Type {
+	t = Unalias(t)
 	tpar, _ := t.(*TypeParam)
 	if tpar == nil {
 		return under(t)
@@ -54,6 +55,7 @@ func coreType(t Type) Type {
 // and strings as identical. In this case, if successful and we saw
 // a string, the result is of type (possibly untyped) string.
 func coreString(t Type) Type {
+	t = Unalias(t)
 	tpar, _ := t.(*TypeParam)
 	if tpar == nil {
 		return under(t) // string or untyped string
diff --git a/src/internal/types/testdata/fixedbugs/issue67547.go b/src/internal/types/testdata/fixedbugs/issue67547.go
index cca8ba2367..b95be4faeb 100644
--- a/src/internal/types/testdata/fixedbugs/issue67547.go
+++ b/src/internal/types/testdata/fixedbugs/issue67547.go
@@ -8,3 +8,15 @@ func _[P int]() {
 	type A = P
 	_ = A(0) // don't crash with this conversion
 }
+
+func _[P []int]() {
+	type A = P
+	_ = make(A, 10) // don't report an error for A
+}
+
+func _[P string]() {
+	var t []byte
+	type A = P
+	var s A
+	copy(t, s) // don't report an error for s
+}