diff --git a/src/cmd/compile/internal/types2/literals.go b/src/cmd/compile/internal/types2/literals.go
index b81d51564c..da5b03d8ea 100644
--- a/src/cmd/compile/internal/types2/literals.go
+++ b/src/cmd/compile/internal/types2/literals.go
@@ -129,7 +129,7 @@ func (check *Checker) compositeLit(x *operand, e *syntax.CompositeLit, hint Type
 		typ = hint
 		base = typ
 		// *T implies &T{}
-		if b, ok := deref(coreType(base)); ok {
+		if b, ok := deref(commonUnder(check, base, nil)); ok {
 			base = b
 		}
 		isElem = true
@@ -142,7 +142,7 @@ func (check *Checker) compositeLit(x *operand, e *syntax.CompositeLit, hint Type
 		base = typ
 	}
 
-	switch utyp := coreType(base).(type) {
+	switch utyp := commonUnder(check, base, nil).(type) {
 	case *Struct:
 		// Prevent crash if the struct referred to is not yet set up.
 		// See analogous comment for *Array.
@@ -330,7 +330,7 @@ func (check *Checker) compositeLit(x *operand, e *syntax.CompositeLit, hint Type
 			}
 			var cause string
 			if utyp == nil {
-				cause = " (no core type)"
+				cause = " (no common underlying type)"
 			}
 			check.errorf(e, InvalidLit, "invalid composite literal%s type %s%s", qualifier, typ, cause)
 			x.mode = invalid
diff --git a/src/go/types/literals.go b/src/go/types/literals.go
index d3102d4f91..ebc25957ed 100644
--- a/src/go/types/literals.go
+++ b/src/go/types/literals.go
@@ -133,7 +133,7 @@ func (check *Checker) compositeLit(x *operand, e *ast.CompositeLit, hint Type) {
 		typ = hint
 		base = typ
 		// *T implies &T{}
-		if b, ok := deref(coreType(base)); ok {
+		if b, ok := deref(commonUnder(check, base, nil)); ok {
 			base = b
 		}
 		isElem = true
@@ -146,7 +146,7 @@ func (check *Checker) compositeLit(x *operand, e *ast.CompositeLit, hint Type) {
 		base = typ
 	}
 
-	switch utyp := coreType(base).(type) {
+	switch utyp := commonUnder(check, base, nil).(type) {
 	case *Struct:
 		// Prevent crash if the struct referred to is not yet set up.
 		// See analogous comment for *Array.
@@ -334,7 +334,7 @@ func (check *Checker) compositeLit(x *operand, e *ast.CompositeLit, hint Type) {
 			}
 			var cause string
 			if utyp == nil {
-				cause = " (no core type)"
+				cause = " (no common underlying type)"
 			}
 			check.errorf(e, InvalidLit, "invalid composite literal%s type %s%s", qualifier, typ, cause)
 			x.mode = invalid
diff --git a/src/internal/types/testdata/fixedbugs/issue51335.go b/src/internal/types/testdata/fixedbugs/issue51335.go
index 04dc04e1d7..5eb5213843 100644
--- a/src/internal/types/testdata/fixedbugs/issue51335.go
+++ b/src/internal/types/testdata/fixedbugs/issue51335.go
@@ -8,9 +8,9 @@ type S1 struct{}
 type S2 struct{}
 
 func _[P *S1|*S2]() {
-	_= []P{{ /* ERROR "invalid composite literal element type P (no core type)" */ }}
+	_= []P{{ /* ERROR "invalid composite literal element type P (no common underlying type)" */ }}
 }
 
 func _[P *S1|S1]() {
-	_= []P{{ /* ERROR "invalid composite literal element type P (no core type)" */ }}
+	_= []P{{ /* ERROR "invalid composite literal element type P (no common underlying type)" */ }}
 }