diff --git a/Classes/ShareKit/Core/SHK.m b/Classes/ShareKit/Core/SHK.m
index c9277055..00b9f556 100644
--- a/Classes/ShareKit/Core/SHK.m
+++ b/Classes/ShareKit/Core/SHK.m
@@ -38,6 +38,11 @@
 #import <MessageUI/MessageUI.h>
 #include <sys/xattr.h>
 
+// +++ Working around <rdar://problem/11017158>> by forcing the symbol to be weak import
+// and prevent "dyld: Symbol not found: _NSURLIsExcludedFromBackupKey" when running
+// in iOS ver < 5.1
+extern NSString * const NSURLIsExcludedFromBackupKey __attribute__((weak_import));
+
 NSString * SHKLocalizedStringFormat(NSString* key);
 NSString * const SHKHideCurrentViewFinishedNotification = @"SHKHideCurrentViewFinished";