diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts index df432808f30..3f79f148458 100644 --- a/src/compiler/checker.ts +++ b/src/compiler/checker.ts @@ -4640,7 +4640,9 @@ namespace ts { // and intersection types are further deconstructed on the target side, we don't want to // make the check again (as it might fail for a partial target type). Therefore we obtain // the regular source type and proceed with that. - source = getRegularTypeOfObjectLiteral(source); + if (target.flags & TypeFlags.UnionOrIntersection) { + source = getRegularTypeOfObjectLiteral(source); + } } let saveErrorInfo = errorInfo; @@ -5511,6 +5513,7 @@ namespace ts { regularType.constructSignatures = (type).constructSignatures; regularType.stringIndexType = (type).stringIndexType; regularType.numberIndexType = (type).numberIndexType; + (type).regularType = regularType; } return regularType; }