diff --git a/OpenVPN Adapter/OpenVPNError.h b/OpenVPN Adapter/OpenVPNError.h
index 3cecc42..610c770 100644
--- a/OpenVPN Adapter/OpenVPNError.h	
+++ b/OpenVPN Adapter/OpenVPNError.h	
@@ -8,10 +8,10 @@
 
 #import <Foundation/Foundation.h>
 
-extern NSString * __nonnull const OpenVPNAdapterErrorDomain;
+FOUNDATION_EXPORT NSString * __nonnull const OpenVPNAdapterErrorDomain;
 
-extern NSString * __nonnull const OpenVPNAdapterErrorFatalKey;
-extern NSString * __nonnull const OpenVPNAdapterErrorEventIdentifierKey;
+FOUNDATION_EXPORT NSString * __nonnull const OpenVPNAdapterErrorFatalKey;
+FOUNDATION_EXPORT NSString * __nonnull const OpenVPNAdapterErrorEventIdentifierKey;
 
 /**
  <#Description#>