diff --git a/nj2k/src/org/jetbrains/kotlin/nj2k/conversions/TypeMappingConversion.kt b/nj2k/src/org/jetbrains/kotlin/nj2k/conversions/TypeMappingConversion.kt
index b7af1d1b804..1350d55fd5a 100644
--- a/nj2k/src/org/jetbrains/kotlin/nj2k/conversions/TypeMappingConversion.kt
+++ b/nj2k/src/org/jetbrains/kotlin/nj2k/conversions/TypeMappingConversion.kt
@@ -136,8 +136,10 @@ class TypeMappingConversion(val context: NewJ2kConverterContext) : RecursiveAppl
         else toKotlinTypesMap[fqName]
     }
 
-    private fun JKClassSymbol.kotlinStandardType(): String? =
-        JavaToKotlinClassMap.mapJavaToKotlin(FqName(fqName))?.asString()
+    private fun JKClassSymbol.kotlinStandardType(): String? {
+        if (isKtFunction(fqName)) return fqName
+        return JavaToKotlinClassMap.mapJavaToKotlin(FqName(fqName))?.asString()
+    }
 
     private fun JKJavaPrimitiveType.mapPrimitiveType(): JKClassType {
         val fqName = jvmPrimitiveType.primitiveType.typeFqName
@@ -156,4 +158,10 @@ class TypeMappingConversion(val context: NewJ2kConverterContext) : RecursiveAppl
             else -> false
         }
     }
+
+    companion object {
+        private val ktFunctionRegex = "kotlin\\.jvm\\.functions\\.Function\\d+".toRegex()
+        private fun isKtFunction(fqName: String) =
+            ktFunctionRegex.matches(fqName)
+    }
 }
\ No newline at end of file