diff --git a/Sources/DynamicSchema+Convenience.swift b/Sources/DynamicSchema+Convenience.swift
index 5254d5f2..68d23a39 100644
--- a/Sources/DynamicSchema+Convenience.swift
+++ b/Sources/DynamicSchema+Convenience.swift
@@ -181,6 +181,14 @@ extension DynamicSchema {
                         }
                         else if attribute.isOptional {
 
+                            valueTypeString += "?"
+                            defaultString = " = nil"
+                        }
+                    case .URIAttributeType:
+                        valueTypeString = String(describing: URL.self)
+                        if let defaultValue = (attribute.defaultValue as! URL.QueryableNativeType?).flatMap(URL.cs_fromQueryableNativeType) {
+                            defaultString = " = \"\(defaultValue.absoluteString)\""
+                        } else if attribute.isOptional {
                             valueTypeString += "?"
                             defaultString = " = nil"
                         }