diff --git a/Sources/Unbox.swift b/Sources/Unbox.swift
index 076a4b1..92a173d 100644
--- a/Sources/Unbox.swift
+++ b/Sources/Unbox.swift
@@ -487,14 +487,12 @@ public class Unboxer {
         }
         
         let transformedStringArray = UnboxValueResolver<[String]>(self).resolveOptionalValueForKey(key, isKeyPath: isKeyPath, transform: { stringArray -> [T]? in
-            do {
-                return try stringArray.flatMap {
-                    guard let transformedUnboxedString = T.transformUnboxedString($0) else { throw UnboxValueError.InvalidValue($0, key) }
-                    return transformedUnboxedString
-                }
-            } catch {
-                return nil
+            var transformedStringArray = [T]()
+            for string in stringArray {
+                guard let transformedUnboxedString = T.transformUnboxedString(string) else { return nil }
+                transformedStringArray.append(transformedUnboxedString)
             }
+            return transformedStringArray
         })
         
         if let transformedStringArray = transformedStringArray {