diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index a8af11e7803..990bfd546a3 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -8938,7 +8938,9 @@ namespace ts {
                     !(target.flags & TypeFlags.Union) &&
                     !isIntersectionConstituent &&
                     source !== globalObjectType &&
-                    getPropertiesOfType(source).length > 0 &&
+                    (getPropertiesOfType(source).length > 0 ||
+                     getSignaturesOfType(source, SignatureKind.Call).length > 0 ||
+                     getSignaturesOfType(source, SignatureKind.Construct).length > 0) &&
                     isWeakType(target) &&
                     !hasCommonProperties(source, target)) {
                     if (reportErrors) {