diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpander.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpander.kt
index 5e01e42d82d..1d5308a54f6 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpander.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/TypeAliasExpander.kt
@@ -113,13 +113,15 @@ class TypeAliasExpander(
     ): TypeProjection {
         val type = originalProjection.type
 
-        if (!type.requiresTypeAliasExpansion()) {
+        if (type.isError || !type.requiresTypeAliasExpansion()) {
             return originalProjection
         }
 
         val typeConstructor = type.constructor
         val typeDescriptor = typeConstructor.declarationDescriptor
 
+        assert(typeConstructor.parameters.size == type.arguments.size) { "Unexpected malformed type: $type" }
+        
         when (typeDescriptor) {
             is TypeParameterDescriptor -> {
                 return originalProjection