diff --git a/client/iOS/Additions/TSXAdditions.m b/client/iOS/Additions/TSXAdditions.m
index b1016a4ef..c0dc878e2 100644
--- a/client/iOS/Additions/TSXAdditions.m
+++ b/client/iOS/Additions/TSXAdditions.m
@@ -11,6 +11,7 @@
 #import "TSXAdditions.h"
 #include <openssl/bio.h>
 #include <openssl/evp.h>
+#include <openssl/err.h>
 
 @implementation NSObject (TSXAdditions)